Part IX Backing Up and Restoring Data

This part provides instructions for backing up and restoring data in the Solaris environment. This part contains these chapters.

Chapter 33 Backing Up and Restoring File Systems (Overview)

This chapter provides guidelines and planning information on backing up and restoring complete file systems using the ufsdump and ufsrestore commands.

This is a list of overview information in this chapter.

• "What's New in Backing Up and Restoring File Systems"

• "Where to Find Backup and Restore Tasks"

• "Definition: Backing Up and Restoring File Systems"

• "Why You Should Back Up File Systems"

• "Choosing a Tape Device"

• "Planning Which File Systems to Back Up"

• "Overview of the Backup and Restore Commands"

• "Choosing the Type of Backup"

• "Guidelines For Scheduling Backups"

• "Sample Backup Schedules"

What's New in Backing Up and Restoring File Systems

Use the nisbackup and nisrestore commands to backup and restore a NIS+ master server running the Solaris 2.5 release or later. See Solaris Naming Administration Guide for information on using these commands.

Where to Find Backup and Restore Tasks

Use these references to find step-by-step instructions for backing up and restoring file systems (using the ufsdump and ufsrestore commands).

• Chapter 34, Backing Up Files and File Systems (Tasks)

• Chapter 35, Restoring Files and File Systems (Tasks)

Definition: Backing Up and Restoring File Systems

Backing up file systems means copying file systems to removable media (such as tape) to safeguard against loss, damage, or corruption. Restoring file systems means copying reasonably-current backup files from removable media to a working directory.

This chapter describes the commands for scheduled backup and restore operations (ufsdump and ufsrestore); however, there are other commands you can use for copying files and file systems for sharing or transporting files. Table 33-1 provides pointers to all commands that copy individual files and/or file systems to media.

Why You Should Back Up File Systems

Backing up files is one of the most crucial system administration functions. You should perform regularly-scheduled backups to prevent loss of data due to:

• System crashes

• Accidental deletion of files

• Hardware failures

• Natural disasters (for example, fire, hurricanes)

• Problems when reinstalling or upgrading a system

Choosing a Tape Device

Table 33-2 shows typical tape devices used for storing file systems during the backup process. For more detailed information on tape devices, see Chapter 38, Managing Tape Drives (Tasks).

Planning Which File Systems to Back Up

You should back up any file systems that are critical to users, including file systems that change frequently. Table 33-3 and Table 33-4 provide general guidelines on the file systems to back up for standalone systems and servers.

You do not need to back up a server's /export/swap file system.

Overview of the Backup and Restore Commands

The ufsdump and ufsrestore commands are the recommended commands for scheduled backups of complete file systems. Table 33-5 lists the tasks you can perform with them. For information on how these commands work and their syntax, see Chapter 36, The ufsdump and ufsrestore Commands (Reference).

Choosing the Type of Backup

With the ufsdump command, you can perform full or incremental backups. Table 33-6 lists the differences between these types of backup procedures.

Guidelines For Scheduling Backups

A backup schedule is the schedule you establish to run the ufsdump command. This section provides guidelines on the factors to weigh when creating a backup schedule, guidelines on how often to back up file systems, and sample backup schedules.

What Drives a Backup Schedule

The schedule you create depends on:

• Your need to minimize the number of tapes

• Time available for doing backups

• Time available to do a full restore of a damaged file system

• Time available for retrieving individual files that get accidentally deleted

How Often Should You Backup?

If you do not need to minimize time and media spent on backups, you can do full backups every day. However, this is not realistic for many sites, so incremental backups are most often used. In this case, it is recommended that you back up your site to be able to restore files from the last four weeks. This requires at least four sets of tapes--one for each week, which you would reuse each month. In addition, you should archive the monthly backups for at least a year, and then keep a yearly backup for a number of years.

Using Dump Levels to Create Incremental Backups

The dump level you specify in the ufsdump command (0-9) determines which files are backed up. Specifying dump level 0 creates a full backup. Numbers 1-9 are used to schedule incremental backups, but have no defined meanings. Numbers 1-9 are just a range of numbers used to schedule cumulative or discrete backups. The only meaning levels 1-9 have is in relationship to each other, as a higher or lower number.

The following examples show the flexibility of the incremental dump procedure using levels 1-9.

Dump Levels For Daily, Cumulative Backups

Doing daily, cumulative incremental backups is the most commonly used backup scheme and is recommended for most situations. The following example shows a schedule using a level 9 dump each day, and a level 5 dump on Friday to restart the process.

In the following example, you could have used other numbers in the 1-9 range to produce the same results. The key is having the same number each day, with any lower number on Friday. For example, you could have specified levels 4, 4, 4, 4, 2 or 7, 7, 7, 7, 5.

Figure 33-1 Incremental Backup: Daily Cumulative

Dump Levels For Daily, Discrete Backups

The following example shows a schedule where you capture only a day's work on different tapes. In this case, sequential dump level numbers are used during the week (3,4,5,6) with a lower number (3) on Friday.

In the following example, you could have used the sequence 6,7,8,9 followed by 2, or 5,6,7,8 followed by 3. Remember, the number themselves have no defined meaning; you attribute meaning by ordering them in a high/low sequence.

Figure 33-2 Incremental Backup: Daily Discrete

Sample Backup Schedules

This section provides sample backup schedules. All schedules assume you begin with a full backup (level 0), and that you use the -u option to record each backup.

Example--Daily Cumulative, Weekly Cumulative Backups

Table 33-7 shows the most commonly used incremental backup schedule; it is recommended for most situations.

With this schedule:

• Each weekday tape accumulates all files changed since the end of the previous week (or the initial level 0 for the first week).

• Each Friday's tape contains all the files changed since the first level 0. For the level 9 backups, the previous level 0 or level 5 is the closest backup at a lower level.

• All files that have changed since the lower-level backup at the end of the previous week are saved each day.

• For each Friday level 5, the nearest lower-level backup is the level 0 done at the beginning of the month. Therefore, each Friday's tape contains all the files changed during the month to that point.

• Table 33-8 shows how the contents of the tapes can change across two weeks.

Example--Daily Cumulative, Weekly Incremental Backups

Table 33-9 shows a schedule where each weekday tape accumulates all files that changed since the beginning of the week (or the initial level 0 for the first week), and each Friday's tape contains all the files changed that week.

Table 33-10 shows how the contents of the tapes can change across two weeks.

Tape Needs

With this schedule, you will need six tapes (if you want to reuse daily tapes), or nine tapes (if you want to use four different daily tapes): one for the level 0, four for the Fridays, and one or four daily tapes.

If you need to restore a complete file system, you will need five tapes: the level 0, all preceding Friday tapes (three), and the most recent daily tape.

Example--Daily Incremental, Weekly Cumulative Backups

Table 33-11 shows a schedule where each weekday tape contains only the files changed since the previous day, and each Friday's tape contains all files changed since the initial level 0 at the beginning of the month.

Table 33-12 shows how the contents of the tapes can change across two weeks.

Tape Needs

With this schedule you will need at least nine tapes: one for the level 0, four for the Fridays, and four daily tapes, assuming you reuse daily tapes each week, which is not recommended. If you save the weekly tapes for a month, you need 21 tapes.

If you need to restore the complete file system, you need six tapes: the level 0, the most recent Friday tape, and all the daily tapes for that week.

Example--Backup Schedule for a Server

Table 33-13 shows an example backup strategy for a heavily-used file server on a small network where users are doing file-intensive work, such as program development or document production. It assumes that the backup period begins on a Sunday and consists of four seven-day weeks.

With this plan, you use 4n tapes (the number of tapes needed for four full backups of root (/), /usr, /export, and /export/home), plus 24 additional tapes for the incremental backups of /export/home. This plan assumes that each incremental backup uses one tape and you save the tapes for a month.

Here's how this plan works:

1. On each Sunday, do a full backup (level 0) of root (/), /usr, /export, and /export/home. Save the level 0 tapes for at least 3 months.

2. On the first Monday of the month, use tape A to do a level 9 backup of /export/home. ufsdump copies all files changed since the previous lower-level backup (in this case, the level 0 backup that you did on Sunday).

3. On the first Tuesday of the month, use tape B to do a level 9 backup of /export/home. Again, ufsdump copies all files changed since the last lower-level backup--Sunday's level 0 backup.

4. On the first Wednesday, use tape C to do a level 5 backup. ufsdump copies all files changed since Sunday.

5. Do the Thursday and Friday level 9 backups on tapes D and E. ufsdump copies all files changed since the last lower-level backup--Wednesday's level 5 backup.

6. On the first Saturday of the month, do a level 5 backup of /export/home, which copies all files changed since the previous lower-level backup--in this case, the level 0 backup you did on Sunday. Store tapes A-F until the first Monday of the next 4-week period, when you use them again.

7. Repeat steps 1-6 for the next three weeks, using tapes G-L and 4n tapes for the level 0 on Sunday, and so on.

8. For each 4-week period, repeat steps 1-7, using a new set of tapes for the level 0s and reusing tapes A-X for the incremental backups. The level 0 tapes could be reused after 3 months.

   This plan lets you save files in their various states for a month. It requires many tapes, but ensures that you have a library of tapes to draw upon. To reduce the number of tapes, you could reuse Tapes A-F each week.

Other Backup Scheduling Recommendations

Table 33-14 provides other recommendations for scheduling backups.

Chapter 34 Backing Up Files and File Systems (Tasks)

This chapter describes the procedures for backing up file systems using the ufsdump command.

This is a list of the step-by-step instructions in this chapter.

• "How to Find File System Names"

• "How to Determine the Number of Tapes for Full Backup"

• "How to Do Backups on Cartridge Tape"

For detailed information on syntax, options, and arguments for the ufsdump command, see Chapter 36, The ufsdump and ufsrestore Commands (Reference).

Preparing to Do Backups

Preparing to back up file systems begins with planning, which is described in Chapter 33, Backing Up and Restoring File Systems (Overview) and covers choosing:

• A tape drive

• Which file systems to back up

• The type of backup (full or incremental)

• A backup schedule

This section describes other tasks you may need to perform before backing up file systems including:

• Finding names of file systems to back up

• Determining the number of tapes for a full backup

How to Find File System Names

1. Display the contents of the /etc/vfstab file.

   $ more /etc/vfstab

2. Look in the mount point column for the name of the file system.

3. You will use the mount point in the mount point column when you back up the file system.

Example--Finding File System Names

$ more /etc/vfstab
#device         device            mount    FS   fsck  mount  mount
#to mount       to fsck           point    type pass at boot options
#
/proc             -                  /proc proc   -    no      -
swap              -                  /tmp  tmpfs  -    yes     -
/dev/dsk/c0t3d0s0 /dev/rdsk/c0t3d0s0 /     ufs    1    no      -
/dev/dsk/c0t3d0s1 -                  -     swap   -    no      -
/dev/dsk/c0t1d0s6 /dev/rdsk/c0t1d0s6 /usr  ufs    2    no      -
mars:/share/kit -                    /kit  nfs    -    yes     -
mars:/db/doc    -                  /db/doc nfs    -    yes     -

How to Determine the Number of Tapes for Full Backup

1. Become superuser.

2. Estimate the size of the backup in bytes by using the usfdump S command.

   # ufsdump S filesystem

   S	Displays the estimated number of bytes needed to do the backup.

3. Divide the estimated size by the capacity of the tape to see how many tapes you need.

   See Table 33-2 for a list of tape capacities.

Example--Determining Number of Tapes

In this example, the file system of 489472 bytes will fit on a 150-Mbyte tape.

# ufsdump S /export/home
489472

Doing Backups

The following are general guidelines for performing backups:

• Use single-user mode or unmount the file system.

• Be aware that backing up file systems when there are directory-level operations (such as creating, removing, and renaming files) and file-level activity means some data will not be included in the backup.

• You can run the ufsdump command from a single system and remotely back up groups of systems across the network through remote shell or remote login, and direct the output to the system on which the tape drive is located. (Typically, the tape drive is located on the system from which you run the ufsdump command, but it does not have to be.)

  Another way to back up files to a remote drive is to pipe the output from the ufsdump command to the dd command. See Chapter 37, Copying UFS Files and File Systems (Tasks), for information about using the dd command.

• If you are doing remote backups across the network, the system initiating the backup must have entries in its /.rhosts file for the hosts it will back up.

• To specify a remote drive on a system, use the naming convention that matches the OS release of the system with the remote tape drive. For example, use /dev/rst0 for a remote drive on a system running the SunOS 4.1.x release; use /dev/rmt/0 for a system running the Solaris 2.x release.

Use the nisbackup command to backup a NIS+ master server running the Solaris 2.5 release or later. See Solaris Naming Administration Guide for information on using this command.

How to Do Backups on Cartridge Tape

The following steps provide the general steps for backing up file systems using the ufsdump command. The examples show specific uses of options and arguments.

1. Become superuser.

2. Shut down the system.

   # init 0

3. Bring the system to run level S (single-user mode).

   ok boot -s

4. [Optional] Check the file system for consistency with the fsck command.

   Running the fsck command using the -m option checks for consistency of file systems. For example, power failures can leave files in an inconsistent state. For more information on the fsck command, see Chapter 31, Checking File System Integrity.

   # fsck -m /dev/rdsk/ device-name

5. If you will be backing up file systems onto a remote tape drive:

   1. Add the following entry to the ./rhosts file of the system that is initiating the backup:

      host root

   2. Verify that the host name added to the /.rhosts file above is accessible via the local /etc/inet/hosts file or available from the NIS or NIS+ name server.

6. Identify the device name of the tape drive.

   The default tape drive is /dev/rmt/0.

7. Insert a tape that is not write protected into the tape drive.

8. Back up file systems using the ufsdump command.

   Use the following table to select the most common options and arguments for the ufsdump command. See Chapter 36, The ufsdump and ufsrestore Commands (Reference) for other options and arguments.

   To ...	Use This Option or Argument ...	For Example ...	See ...
   Do a full backup	0 option	ufsdump 0ucf /dev/rmt/n files	"Example--Full Backup, root (/), Cartridge Tape"
   Do an incremental backup	1-9 option	ufsdump 9ucf /dev/rmt/n files	"Example--Incremental Backup, root (/) "
   Back up individual files	filename argument	ufsdump 9ucf /dev/rmt/n /export/home/user1/mail	"Example--Full Backup, Individual Home Directory"
   Record dumps to /etc/dumpdates file	-u option (updates file)	ufsdump 9ucf /dev/rmt/n files	"Example--Incremental Backup, root (/) "
   Specify a cartridge tape	-c option	ufsdump 9ucf /dev/rmt/n files	"Example--Incremental Backup, root (/) "
   Specify the tape drive	-f dump-file	ufsdump 9ucf /dev/rmt/1 files	"Example--Incremental Backup, root (/) "
   Back up local file systems to a remote host's tape device	remote-host: argument	ufsdump 0ucf mars:/dev/rmt/0 files	"Example--Full Backup to Remote System (Solaris 2.x Data to Solaris 2.x System)"

9. When prompted, remove the tape and replace with the next volume.

10. Label each tape with the volume number, level, date, system name, and file system.

11. Bring the system back to run level 3 by pressing Control-d.

12. Verify the backup was successful by using the ufsrestore command to display the tape contents.

    This command is described in Chapter 35, Restoring Files and File Systems (Tasks).

Example--Full Backup, root (/), Cartridge Tape

In this example, a full backup of the root (/) file system is made on a 150-Mbyte cartridge tape (/dev/rmt/0).

# init 0
ok boot -s
# ufsdump 0ucf /dev/rmt/0 /
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 0 dump: Wed Nov 06 15:32:21 1996
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t3d0s0 (mars:/) to /dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Estimated 41236 blocks (20.13MB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 41200 blocks (20.12MB) on 1 volume at 95 KB/sec
  DUMP: DUMP IS DONE
  DUMP: Level 0 dump on Wed Nov 06 15:32:21 1996
# ufsrestore tf /dev/rmt/0 (Verification starts here)
         2	.
         3	./lost+found
      5696	./usr
     11392	./export
     17088	./opt
     22784	./var
     28480	./var/sadm
     34176	./var/sadm/install
     39872	./var/sadm/install/admin
     39879	./var/sadm/install/admin/default
                      .
                      .
                      .
    #
# (Press Control-D to bring system to run level 3)

Example--Full Backup, /export/home, 4-mm DAT Tape

In this example, a full backup of the /export/home file system is made on a 4-mm DAT tape.

# ufsdump 0ucf /dev/rmt/0 /export/home
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 0 dump: Wed Nov 06 16:18:08 1996
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t3d0s7 (mars:/export/home) to /dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Estimated 13504 blocks (6.59MB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 13480 blocks (6.58MB) on 1 volume at 92 KB/sec
  DUMP: DUMP IS DONE
  DUMP: Level 0 dump on Wed Nov 06 16:18:08 1996
# ufsrestore tf /dev/rmt/0
    113920	./x97_sysmgt
    159488	./kryten
    159489	./kryten/.login
    159490	./kryten/.cshrc
    170880	./kryten/directives
    170882	./kryten/directives/directive.2001
    170883	./kryten/directives/directive.450b
    170881	./kryten/directives/directive.115c
    159491	./kryten/tar_file
          .
          .
          .
#

Example--Incremental Backup, root (/)

In this example, an incremental backup of the root (/) file system is made on a 4-mm DAT tape device.

# ufsdump 9ucf /dev/rmt/0 /
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 9 dump: Wed Nov 06 16:14:51 1996
  DUMP: Date of last level 0 dump: Wed Nov 06 15:32:21 1996
  DUMP: Dumping /dev/rdsk/c0t3d0s0 (mars:/) to /dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Estimated 3708 blocks (1.81MB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 3652 blocks (1.78MB) on 1 volume at 75 KB/sec
  DUMP: DUMP IS DONE
  DUMP: Level 9 dump on Wed Nov 06 16:14:51 1996
 # ufsrestore tf /dev/rmt/0
         2	   .
     10752	   ./var
     13440	   ./var/sadm
      2689	   ./var/sadm/install
      2690	   ./var/sadm/install/.lockfile
      2766	   ./var/sadm/install/contents
     10753	   ./var/sadm/pkg
      2734	   ./var/adm
      2780	   ./var/adm/sa
      2951	   ./var/adm/sa/sa24
      2735	   ./var/cron
      2885	   ./var/cron/log
      8086	   ./var/spool
      8087	   ./var/spool/locks
      8088	   ./var/tmp
#

Example--Full Backup, Individual Home Directory

In this example, a full backup of the /export/home/kryten directory is made on a 4-mm DAT tape.

# ufsdump 0ucf /dev/rmt/0 /export/home/kryten
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 0 dump: Wed Nov 06 16:12:41 1996
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t3d0s7 (mars:/export/home) to 
/dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Estimated 280 blocks (140KB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 250 blocks (125KB) on 1 volume at 15 KB/sec
  DUMP: DUMP IS DONE
# ufsrestore tf /dev/rmt/0
         2	   .
      2688	   ./kryten
      5409	   ./kryten/letters
      5410	   ./kryten/letters/letter1
      5411	   ./kryten/letters/letter2
      5412	   ./kryten/letters/letter3
      2689	   ./kryten/.profile
      8096	   ./kryten/memos
        30	   ./kryten/reports
        31	   ./kryten/reports/reportA
        32	   ./kryten/reports/reportB
        33	   ./kryten/reports/reportC
#

Example--Full Backup to Remote System (Solaris 2.x Data to Solaris 2.x System)

In this example, the local /export/home file system on a Solaris 2.x system is backed up to a tape device on a remote Solaris 2.x system called pluto.

# ufsdump 0ucf pluto:/dev/rmt/0 /export/home
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 0 dump: Fri Oct 25 10:30:53 1996
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t3d0s7 (/export/home) to (pluto:
/dev/rmt/0).
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 19574 blocks (9.56MB)
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: level 0 dump on Fri Oct 25 10:30:53 1996
  DUMP: Tape rewinding
  DUMP: 19574 blocks (9.56MB) on 1 volume at 92 KB/sec
  DUMP: DUMP IS DONE
# ufsrestore tf pluto:/dev/rmt/0
         2	.
         3	./lost+found
      2688	./kryten
      5409	./kryten/letters
      5410	./kryten/letters/letter1
      5411	./kryten/letters/letter2
      5412	./kryten/letters/letter3
      2689	./kryten/.profile
      8096	./kryten/memos
        30	./kryten/reports
        31	./kryten/reports/reportA
        32	./kryten/reports/reportB
        33	./kryten/reports/reportC
              .
              .
              .
#

Example--Full Backup to Remote System (Solaris 2.x Data to Sun 4.1.x System)

In this example, the local /export/home file system on a Solaris 2.x system is backed up to a tape device on a remote SunOS 4.1.x system (mars). Notice the SunOS 4.x-style device name (/dev/rst0) used with the ufsdump command. To run the ufsdump command, you would log in as superuser on the Solaris 2.x system.

# ufsdump 0ucf mars:/dev/rst0 /export/home
  DUMP: Writing 63 Kilobyte records
  DUMP: Date of this level 0 dump: Fri Oct 25 15:06:47 1996
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t3d0s7 (/export/home) to (mars:
/dev/rst0).
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 19574 blocks (9.56MB)
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: level 0 dump on Fri Oct 25 15:06:47 1996
  DUMP: Tape rewinding
  DUMP: 19574 blocks (9.56MB) on 1 volume
  DUMP: DUMP IS DONE
#
 
 ufsrestore tf mars:/dev/rst0
         2      .
         3      ./lost+found
      2688      ./kryten
      5409      ./kryten/letters
      5410      ./kryten/letters/letter1
      5411      ./kryten/letters/letter2
      5412      ./kryten/letters/letter3
      2689      ./kryten/.profile
      8096      ./kryten/memos
        30      ./kryten/reports
        31      ./kryten/reports/reportA
        32      ./kryten/reports/reportB
        33      ./kryten/reports/reportC
                .
                .
                .
#

Example--Full Backup to Remote System (SunOS 4.1.x Data to Solaris 2.x)

In this example, the local root (/) file system on a Sun 4.1.x system (mars) is backed up to a remote tape device on a Solaris 2.x system called pluto.

Notice that when you back up data to a SunOS 4.1.x system, you must use the dump command--not the ufsdump command.

mars# dump 0ucf pluto:/dev/rmt/0 /
  DUMP: Date of this level 0 dump: Tue Oct 25 16:05:19 1996   
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rsd2a (/) to /dev/rmt/0 on host pluto
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 8686 blocks (4.24MB) on 0.10 tape(s).
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: level 0 dump on Tue Oct 25 16:05:19 1996
  DUMP: Tape rewinding
  DUMP: 8690 blocks (4.24MB) on 1 volume
  DUMP: DUMP IS DONE
mars# restore tf pluto:/dev/rmt/0
         2      .
         3      ./lost+found
      3776      ./export
      7552      ./home
     11328      ./usr
     15104      ./pcfs
      3777      ./tftpboot
      3778      ./tftpboot/tftpboot
      3794      ./tftpboot/boot.sun4c.sunos.4.1.3
      7553      ./etc
      7554      ./etc/sendmail.cf
      7555      ./etc/aliases
      7556      ./etc/aliases.dir
      7557      ./etc/aliases.pag
      7558      ./etc/holidays
      7559      ./etc/dumpdates
                      .
                .
                .
mars#

Chapter 35 Restoring Files and File Systems (Tasks)

This chapter describes the procedures for restoring file systems.

This is a list of step-by-step instructions in this chapter.

• "How to Determine Which Tapes to Use"

• "How to Restore Files Interactively"

• "How to Restore Specific Files"

• "How to Use a Remote Drive to Restore Files"

• "How to Restore a Complete File System"

• "How to Restore the root (/) and /usr File Systems"

This chapter describes how to use the ufsrestore(1M) command to restore files and file systems that were backed up using the ufsdump command. See Chapter 37, Copying UFS Files and File Systems (Tasks), for information about other commands you can use to archive, restore, copy, or move files and file systems.

Preparing to Restore Files and File Systems

The ufsrestore command copies files from backups created using the ufsdump command into the current working directory. You can use ufsrestore to reload an entire file system hierarchy from a level 0 dump and incremental dumps that follow it or to restore one or more single files from any dump tape. If ufsrestore is run by superuser, files are restored with their original owner, last modification time, and mode (permissions).

Before you start to restore files or file systems, you need to know:

• Which tapes (or diskettes) you need

• The raw device name for the file systems you want to back up

• The type of tape drive you will use

• The device name (local or remote) for the tape drive

Determining the Disk Device Name

If you have properly labeled your backup tapes, you should be able to use the disk device name (/dev/rdsk/devicename) from the tape label. See "How to Find File System Names" for more information.

Determining the Type of Tape Drive You Will Use

You must use a tape drive that is compatible with the backup media to restore the files. The format of the backup media determines which drive you must use to restore files. For example, if your backup media is 8-mm tape, you must use an 8-mm tape drive to restore the files.

Determining the Tape Device Name

You may have specified the tape device name (/dev/rmt/n) as part of the backup tape label information. If you are using the same drive to restore a backup tape, you can use the device name from the label. See Chapter 38, Managing Tape Drives (Tasks) for more information on media devices and device names.

Restoring Complete File Systems

Occasionally, a file system becomes so damaged that you must completely restore it. Typically, you need to restore a complete file system after a disk head crash. You may need to replace the hardware before you can restore the software. See Chapter 23, SPARC: Adding a Disk (Tasks), or Chapter 24, x86: Adding a Disk (Tasks) for information on how to replace a disk. Fully restoring a file system such as /export/home can take a lot of time. If you have consistently backed up file systems, you can restore them to their state at the last incremental backup.

Restoring Individual Files and Directories

This section describes how to restore individual files and directories using a local tape drive. See "How to Use a Remote Drive to Restore Files" for information on how to use a remote drive to restore files.

When you restore files in a directory other than the root directory of the file system, ufsrestore recreates the file hierarchy in the current directory. For example, if you restore files to /home1 that were backed up from /home/doc/books the files are restored in the /home1/doc/books directory.

When restoring individual files and directories, it is a good idea to restore them to a temporary location, such as the /var/tmp directory. After you verify them, you can move the files to their proper locations. You can restore individual files and directories to their original locations. If you do so, be sure you are not overwriting newer files with older versions from the backup tape.

Do not restore files in the /tmp directory even temporarily. The /tmp directory is usually mounted as a TMPFS file system and it does not support UFS file system attributes such as ACLs.

Using a Remote Drive to Restore Files

You can restore files from a remote drive by adding remote-host: to the front of the tape device name. Here is the syntax:

ufsrestore rf [user@]remote-host:/dev/rmt/unit filename 

For example, to access /dev/rmt/0 on the system venus, type:

# ufsrestore rf venus:/dev/rmt/0 filename

Restoring File Systems

Things you need to know:

• Which tapes have the files to be restored

• The path name of the files to be restored

How to Determine Which Tapes to Use

1. Ask the user the date when the file or file system was lost, or the approximate date the files to be recovered were last modified.

2. Refer to your backup plan to find the date of the last backup that would have the file or file system on it.

   To retrieve the most recent version of a file, work backward through the incremental backups from highest to lowest level and most recent to least recent, unless the user requests otherwise.

3. If you have online archive files, use the ufsrestore command to identify correct media.

   # ufsrestore ta archive-name ./path/filename ./path/filename

   t	List each file that appears on the tape.
   a	Reads the table of contents from the online archive file instead of the tape.
   archive-name	Identifies the online archive file name.
   ./path/filename	Identifies the file name(s) you are looking for on the online archive. If successful, ufsrestore will print out the inode number and file name. If unsuccessful, ufsrestore will print an error message.

4. Insert the media containing the backups in the drive and use the ufsrestore command to verify the correct media.

   # ufsrestore tf device-name ./path/filename ./path/filename

   Be sure to use the complete path for the filename(s). If a file is in the backup, its name and inode number is listed. Otherwise, a message says it is not on the volume.

5. If you have multiple dump files on the same tape, use the s /dev/rmt/n option to position the tape at the dump you want to use.

   # ufsrestore xfs /dev/rmt/n tape_number

Example--Determining Which Tapes to Use

If you use ufsdump to dump the /usr file system, the table of contents lists only the files and directories under /usr. To see if /usr/bin/pwd is in the online archive, type:

# ufsrestore ta archive-name ./bin/pwd

To see if /usr/bin/pwd is on the backup tape, type:

# ufsrestore tf /dev/rmt/n ./bin/pwd

How to Restore Files Interactively

1. Become superuser.

2. Write-protect the tape.

3. Put the backup tape in the tape drive.

4. Change to a directory that will be used to restore the files temporarily.

   # cd /var/tmp

   If you want to restore the files to a different directory, substitute the directory name for /var/tmp in this step.

5. Use the ufsrestore command to start the interactive restoration.

   Some informational messages and the ufsrestore> prompt are displayed.

   # ufsrestore if /dev/rmt/n

6. Create a list of files to be restored.

   1. List the contents of a directory.

      ufsrestore> ls directory

   2. Change to a directory.

      ufsrestore> cd directory-name

   3. Create a list of files and directories you want to restore.

      ufsrestore> add filename filename

   4. [Optional] If you need to remove a directory or file name from the list of files to be restored, use the delete command.

      ufsrestore> delete filename

7. Turn on verbose mode to display the file names as they are being restored.

   ufsrestore> verbose

8. Use the extract command after the list is complete.

   ufsrestore> extract

   The ufsrestore command asks you which volume number to use.

9. Type the volume number and press Return. If you have only one volume, type 1 and press Return.

   Specify next volume #: 1

   The files and directories in the list are extracted and restored to the current working directory.

10. To keep the mode of the current directory unchanged, enter n at the set owner/mode prompt.

    set owner/mode for `.'? [yn] n

11. Quit the ufsrestore program.

    ufsrestore> quit

    The shell prompt is displayed.

12. Verify the files are restored.

    1. List the restored files and directories.

       # ls -l

       A list of files and directories is displayed.

    2. Check the list to be sure all the files and directories you specified in the list have been restored.

    3. Move the files to the proper directories.

Example--Restoring Files Interactively

In this example, the files /etc/passwd and /etc/shadow are extracted from the backup tape.

# cd /var/tmp
# ufsrestore if /dev/rmt/0
ufsrestore> ls
.:
 .OWdefaults         bin         lib            sbin/
 .Xauthority         dev/        lost+found/    shared/
 .desksetdefaults    devices/    misc/          tmp/
 .fm/                etc/        mnt/           ufsboot
 .mailtool-init      export/     net/           usr/
 .openwin-init       home/       nfs/           var/
 .profile            hsfsboot    opt/           ws/
 .wastebasket/       kadb        proc/
 .xsun.pluto:0       kernel/
ufsrestore> cd etc
ufsrestore> add passwd shadow
ufsrestore> verbose
verbose mode on
ufsrestore> extract
Extract requested files
You have not read any volumes yet.
Unless you know which volume your file(s) are on you should start 
with the last volume and work towards the first.
Specify next volume #: 1
extract file ./etc/shadow
extract file ./etc/passwd
Add links
Set directory mode, owner, and times.
set owner/mode for `.'? [yn] n
ufsrestore> quit
# 

How to Restore Specific Files

1. Become superuser.

2. Write-protect the tape for safety.

3. Put the backup tape in the tape drive.

4. Change to a directory for restoring files temporarily.

   # cd /var/tmp

   If you want to restore the files to a different directory, substitute the directory name for /var/tmp in this step.

5. Use the ufsrestore command to restore the file.

   # ufsrestore xvf /dev/rmt/n filename ...

   x	Tells ufsrestore to copy specific files or directories in the filename argument.
   v	Displays the file names as they are restored.
   f /dev/rmt/n	Identifies the tape device name.
   filename ...	One or more individual file or directory names separated by spaces, for example: ./export/home/user1/mail ./export/home/user2/mail.

6. Type the volume number where files are located and press Return.

   Specify next volume #: 1

   The file is restored to the current working directory.

7. To keep the mode of the current directory unchanged, type n and press Return at the set owner/mode prompt.

   set owner/mode for '.'? [yn] n

8. Verify the file is restored.

   1. List the current directory.

      # ls -l filename

      A listing for the file is displayed.

   2. Move the file to the proper directory.

      # mv filename /directory/filename

Example--Restoring Specific Files

In this example, the passwd and shadow files are restored to the /var/tmp directory.

# cd /var/tmp
# ufsrestore xvf /dev/rmt/0 ./etc/passwd ./etc/shadow
Verify volume and initialize maps
Media block size is 126
Dump   date: Wed Nov 06 15:21:10 1996
Dumped from: the epoch
Level 0 dump of / on pluto:/dev/dsk/c0t3d0s0
Label: none
Extract directories from tape
Initialize symbol table.
Warning: ./etc: File exists
Extract requested files
You have not read any volumes yet.
Unless you know which volume your file(s) are on you should start 
with the last volume and work towards the first.
Specify next volume #: 1
extract file ./etc/passwd
Add links
Set directory mode, owner, and times.
set owner/mode for `.'? [yn] n
# cd etc
#  mv passwd /etc
# mv shadow /etc
# ls -l etc

How to Use a Remote Drive to Restore Files

You can restore files from a remote drive by adding remote-host: to the front of the tape device name. Here is the syntax:

ufsrestore rf [user@]remote-host:/dev/rmt/n filename 

For example, to access a remote tape drive /dev/rmt/0 on the system venus, type:

# ufsrestore rf venus:/dev/rmt/0 filename

How to Restore a Complete File System

You cannot use this procedure to restore root (/) or /usr. See "How to Restore the root (/) and /usr File Systems" for instructions on restoring these file systems.

1. Become superuser.

2. If necessary, unmount the file system.

   # umount /dev/rdsk/device-name

3. Create the new file system with the newfs command.

   # newfs /dev/rdsk/device-name

   You are asked if you want to construct a new file system on the raw device. Verify that the device-name is correct so you don't wipe out the wrong file system.

4. Confirm that the new file system should be created.

   newfs: construct a new file system /dev/rdsk/cwtxdysz: (y/n)? y

   The new file system is created.

5. Mount the new file system on a temporary mount point.

   # mount /dev/dsk/device-name /mnt

6. Change to the /mnt directory.

   # cd mnt

   You have changed to the mount-point directory.

7. Write-protect the tapes.

8. Insert the first volume of the level 0 tape in the tape drive.

9. Use the ufsrestore command to restore the files on the tapes.

   # ufsrestore rvf /dev/rmt/n

   The level 0 dump is restored. If the dump required multiple tapes, you will be prompted to load the next tape.

10. Remove the tape and load the next tape in the drive.

    Always restore tapes starting with 0 and continuing until you reach the highest level.

11. Use the ufsrestore command to restore the file system.

    # ufsrestore rvf /dev/rmt/n

    The next level tape is restored. If the dump required multiple tapes, you will be prompted to load the next tape.

12. Verify the file system is restored.

    # ls

13. Remove the restoresymtable file.

    # rm restoresymtable

    The restoresymtable file created by ufsrestore is removed.

14. Change to another directory.

    # cd /

15. Unmount the newly restored file system.

    # umount /mnt

16. Remove the last tape and insert a new tape that is not write-protected in the tape drive.

17. Use the ufsdump command to back up the newly restored file system.

    # ufsdump 0uf /dev/rmt/n /dev/rdsk/device-name

    You should always do an immediate backup of a newly created file system because ufsrestore repositions the files and changes the inode allocation.

18. Mount the restored file system.

    # mount /dev/dsk/device-name /mount-point

    The restored file system is mounted and available for use.

19. Verify the restored and mounted file system is available.

    # ls /mount-point

Example--Restoring a Complete File System

In this example, the /export/home file system is restored.

# umount /export/home
# newfs /dev/rdsk/c0t3d0s7
newfs: construct a new file system /dev/rdsk/c0t3d0s7: (y/n)? y
/dev/rdsk/c0t3d0s7:	41040 sectors in 57 cylinders of 9 tracks, 80 sectors
      21.0MB in 4 cyl groups (16 c/g, 5.90MB/g, 2688 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
 32, 11632, 23232, 34832,
# mount /dev/dsk/c0t3d0s7 /mnt
# cd /mnt
# ufsrestore rvf /dev/rmt/0
Verify volume and initialize maps
Media block size is 126
Dump date: Wed Nov 06 16:21:10 1996
Dumped from: the epoch
Level 0 dump of /export/home on pluto:/dev/dsk/c0t3d0s7
Label: none
Begin level 0 restore
Initialize symbol table.
Extract directories from tape
Calculate extraction list.
Warning: ./lost+found: File exists
Make node ./kryten
Make node ./kryten/letters
Make node ./kryten/memos
Make node ./kryten/reports
Make node ./rimmer
Make node ./rimmer/sc.directives
Make node ./rimmer/tests
Make node ./rimmer/answers
Extract new leaves.
Check pointing the restore
# ls
# rm restoresymtable
# cd /
# umount /mnt
# ufsdump 0ucf /dev/rmt/0 /export/home
                    .
 
                    .
 
                    .
# mount /dev/dsk/c0t3d0s7 /export/home
# ls /export/home

How to Restore the root (/) and /usr File Systems

1. Add a new system disk to the system where the root (/) and /usr file systems will be restored.

   For a detailed description about adding a system disk, refer to Chapter 23, SPARC: Adding a Disk (Tasks), or Chapter 24, x86: Adding a Disk (Tasks).

2. Mount the new file system on a temporary mount point.

   # mount /dev/dsk/device-name /mnt

3. Change to the /mnt directory.

   # cd /mnt

4. Create the tape device entries.

   # tapes

5. Write-protect the tapes.

6. Use the ufsrestore command to restore the root file system.

   # ufsrestore rvf /dev/rmt/n

   The level 0 tape is restored.

7. Remove the tape and load the next level tape in the drive.

   Always restore tapes starting with 0 and continuing from lowest to highest level.

8. Continue to use the ufsrestore command as needed.

   # ufsrestore rvf /dev/rmt/n

   The next level tape is restored.

9. Repeat steps 7 and 8 for each additional tape.

10. Verify the file system is restored.

    # ls

11. Remove the restoresymtable file.

    # rm restoresymtable

    Removes the restoresymtable file that is created and used by ufsrestore to check point the restore.

12. Change to the root (/) directory.

    # cd /

13. Unmount the newly created file system.

    # umount /mnt

14. Check the new file system.

    # fsck /dev/rdsk/device-name

    The restored file system is checked for consistency.

15. Create the boot blocks on the root partition by using the installboot command.

    # installboot /usr/platform/`uname-i`/lib/fs/ufs/bootblk /dev/rdsk/devicename

    See "Example--Restoring the root (/) File System on a SPARC System" for an example of using the installboot command on a SPARC system or "Example--Restoring the root (/) File System on an x86 System" for an example of using the installboot command on an x86 system.

16. Insert a new tape in the tape drive.

17. Back up the new file system.

    # ufsdump 0uf /dev/rmt/n /dev/rdsk/device-name

    A level 0 backup is performed. Always do an immediate backup of a newly created file system because ufsrestore repositions the files and changes the inode allocation.

18. Repeat steps 5 through 18 for the /usr file system, if necessary.

19. Reboot the system.

    # init 6

    The system is rebooted.

Example--Restoring the root (/) File System on a SPARC System

# mount /dev/dsk/c0t3d0s0 /mnt
# cd /mnt
# tapes
# ufsrestore rvf /dev/rmt/0
# ls
# rm restoresymtable
# cd /
# umount /mnt
# fsck /dev/rdsk/c0t3d0s0
# installboot /usr/platform/`uname -i`/lib/fs/ufs/bootblk 
/dev/rdsk/c0t3d0s0
# ufsdump 0uf /dev/rmt/0 /dev/rdsk/c0t3d0s0
# init 6

Example--Restoring the root (/) File System on an x86 System

# mount /dev/dsk/c0t3d0s0 /mnt
# cd /mnt
# tapes
# ufsrestore rvf /dev/rmt/0
# ls
# rm restoresymtable
# cd /
# umount /mnt
# fsck /dev/rdsk/c0t3d0s0
# installboot /usr/platform/`uname -i`/lib/fs/ufs/pboot 
/usr/platform/`uname -i`/lib/fs/ufs/bootblk /dev/rdsk/c0t3d0s0
# ufsdump 0uf /dev/rmt/0 /dev/rdsk/c0t3d0s0
# init 6

Chapter 36 The ufsdump and ufsrestore Commands (Reference)

This chapter contains reference information on the ufsdump and ufsrestore commands.

This is a list of reference information in this chapter.

• "How ufsdump Works"

• "Options and Arguments for the ufsdump Command"

• "The ufsdump Command and Security Issues"

• "Options and Arguments for the ufsrestore Command"

How ufsdump Works

The ufsdump command makes two passes when backing up a file system. On the first pass, it scans the raw device file for the file system and builds a table of directories and files in memory. It then writes the table to the backup media. In the second pass, ufsdump goes through the inodes in numerical order, reading the file contents and writing the data to the media.

Determining Device Characteristics

The ufsdump command needs to know only an appropriate block size and how to detect the end of media.

Detecting the End of Media

ufsdump writes a sequence of fixed-size records. When ufsdump receives notification that a record was only partially written, it assumes that it has reached the physical end of the media. This method works for most devices. If a device is not able to notify ufsdump that only a partial record has been written, a media error occurs as ufsdump tries to write.

DAT devices and 8mm tape devices detect end-of-media. Cartridge tape devices and 1/2-inch tape devices do not detect end-of-media.

Copying Data

The ufsdump command copies data only from the raw disk slice. If the file system is still active, anything in memory buffers is probably not copied. The backup done by ufsdump does not copy free blocks, nor does it make an image of the disk slice. If symbolic links point to files on other slices, the link itself is copied.

The Role of the /etc/dumpdates File

The ufsdump command, when used with the -u option, maintains and updates the /etc/dumpdates file. Each line in /etc/dumpdates shows the file system backed up, the level of the last backup, and the day, date, and time of the backup. Here is a typical /etc/dumpdates file from a file server:

/dev/rdsk/c0t3d0s0               0 Wed Nov  6 15:32:21 1996
/dev/rdsk/c0t3d0s0               9 Wed Nov  6 16:14:51 1996
/dev/rdsk/c0t3d0s7               0 Wed Nov  6 16:18:08 1996

When you do an incremental backup, the ufsdump command consults /etc/dumpdates to find the date of the most recent backup of the next lower level. Then it copies to the media all files that were updated since the date of that lower-level backup. After the backup is complete, a new information line, describing the backup you just completed, replaces the information line for the previous backup at that level. On the date that you do a level 0 backup, /etc/dumpdates contains one information line for each backed up file system at each level.

Use the /etc/dumpdates file to verify that backups are being done. This verification is particularly important if you are having equipment problems. If a backup cannot be completed because of equipment failure, the backup is not recorded in the /etc/dumpdates file.

If you need to restore an entire disk, check the /etc/dumpdates file for a list of the most recent dates and levels of backups so that you can determine which tapes you need to restore the entire file system.

The /etc/dumpdates file is a text file that can be edited, but edit it only at your own risk. If you make changes to the file that do not match your archive tapes, you may not be able to find the tapes (or files) you need.

Backup Device (dump-file) Argument

The dump-file argument (to the -f option) specifies the destination of the backup, which can be one of the following:

• Local tape drive or diskette drive

• Remote tape drive or diskette drive

• Standard output

Use this argument when the destination is not the default local tape drive /dev/rmt/0. If you use the -f option, then you must specify a value for dump-file.

The dump-file argument can also point to a file on a local or remote disk, which, if used by mistake, can fill up a file system.

Local Tape or Diskette Drive

Typically, dump-file specifies a raw device file for a tape or diskette drive. When ufsdump writes to an output device, it creates a single backup file which may span multiple tapes or diskettes.

You specify the tape or diskette device on your system using a device abbreviation. The first device is always 0. For example, if you have a SCSI tape controller and one QIC-24 tape drive that uses medium-density formatting, use this device name:

/dev/rmt/0m

When you specify a tape device name, you can also type the letter "-n" at the end of the name to indicate that the tape drive should not rewind after the backup is completed. For example:

/dev/rmt/0mn

Use the "no-rewind" option if you want to put more than one file onto the tape. If you run out of space during a backup, the tape does not rewind before ufsdump asks for a new tape. See "Backup Device Names" for a complete description of device naming conventions.

Remote Tape or Diskette Drive

You specify a remote tape or diskette drive using the syntax host:device. ufsdump writes to the remote device when root on the local system has access to the remote system. If you usually run ufsdump as root, the name of the local system must be included in the /.rhosts file of the remote system. If you specify the device as user@host:device, ufsdump tries to execute as the specified user on the remote system. In this case, the specified user must have a .rhosts file on the remote system to allow the user to access the remote system.

Use the naming convention for the device that matches the operating system for the system on which the device resides, not the system from which you run the ufsdump command. If the drive is on a system that is running a previous SunOS release (for example, 4.1.1), use the SunOS 4.1.x device name (for example, /dev/rst0). If the system is running Solaris software, use the SunOS 5.x convention (for example, /dev/rmt/0).

You must specify remote devices explicitly with the dump-file argument. In previous SunOS releases, the rdump command directed the output to the remote device defined by the dumphost alias. ufsdump does not have an rufsdump counterpart.

Standard Output

When you specify a dash (-) as the dump-file argument, ufsdump writes to the standard output.

The -v option (verify) does not work when the dump-file argument is standard output.

You can use the ufsdump and ufsrestore commands in a pipeline to copy a file system by writing to the standard output with ufsdump and reading from the standard input with ufsrestore, as shown in this example:

# ufsdump 0f - /dev/rdsk/c0t0d0s7 | (cd /home; ufsrestore xf -)

Specifying Files to Back Up

You must always include files-to-backup as the last argument on the command line. This argument specifies the source or contents of the backup. It usually identifies a file system but can also identify individual files or directories.

For a file system, specify the raw device file for a disk slice. It includes the disk controller abbreviation (c), the target number (t) for SCSI devices only, a number indicating the disk number (d), and the slice number (s). For example, if you have a SCSI disk controller on your standalone system (or server) and you want to back up /usr located in slice 6, specify the device as follows:

/dev/rdsk/c0t0d0s6

You can specify the file system by its mount point directory (for example, /home), as long as there is an entry for it in the /etc/vfstab file.

See "Backup Device Names" for a complete description of device naming conventions.

For individual files or directories, type one or more names separated by spaces.

When you use ufsdump to back up one or more directories (rather than a whole file system), a level 0 backup is done. Incremental backups do not apply.

End-of-Media Detection

The ufsdump command automatically detects the end-of-media for most devices. Therefore, you do not usually need to use the -c, -d, -s, and -t options to perform multivolume backups.

The only time you need to use the end-of-media options is when ufsdump does not understand the way the device detects the end-of-media or you are going to restore the files on a system with an older version of the restore command. To ensure compatibility with older versions of the restore command, the size option can still force ufsdump to go to the next tape or diskette before reaching the end of the current tape or diskette.

Specifying Tape Characteristics

If you do not specify any tape characteristics, the ufsdump command uses a set of defaults. Table 36-1 shows some arguments to the ufsdump command that work well for different types of tape cartridges. You can specify tape cartridge (-c), density (-d), size (-s), and number of tracks (-t). Note that you can specify the options in any order as long as the arguments that follow match the order of the options.

Limitations of the ufsdump Command

Table 36-2 lists tasks you cannot perform with the ufsdump command.

Options and Arguments for the ufsdump Command

This section describes in detail the options and arguments for the ufsdump command. The syntax for the ufsdump command is:

/usr/sbin/ufsdump [options] [arguments] files-to-back-up

Default Command Options

If you run the ufsdump command without any options, use this syntax:

# ufsdump files-to-back-up

ufsdump uses these options, by default:

ufsdump 9uf /dev/rmt/0 files-to-back-up

These options do a level 9 incremental backup to the default tape drive at its preferred density.

Options for the ufsdump Command

Table 36-3 describes the options for the ufsdump command.

The /etc/vfstab file does not contain information about how often to back up a file system.

The ufsdump Command and Security Issues

If you are concerned about security:

• Require root access for the ufsdump command.

• Ensure root access entries are removed from /.rhost files on clients and servers if doing centralized backups.

  For general information on security, see Part XIII.

Options and Arguments for the ufsrestore Command

Command Syntax

The syntax of the ufsrestore command is:

ufsrestore [options][arguments][filename ...]

Options and Arguments

You must use one (and only one) of the ufsrestore options shown in Table 36-4.

In addition to one of the options shown in Table 36-4, you can choose from the options shown in Table 36-5.

Commands for Interactive Restore

Chapter 37 Copying UFS Files and File Systems (Tasks)

This chapter describes how to copy UFS files and file systems to disk, tape, and diskettes using various backup commands.

This is a list of the step-by-step instructions in this chapter.

• "How to Clone a Disk (dd)"

• "How to Copy Directories Between File Systems (cpio)"

• "How to Copy Files to a Tape (tar)"

• "How to List the Files on a Tape (tar)"

• "How to Retrieve Files From a Tape (tar)"

• "How to Copy All Files in a Directory to a Tape (cpio)"

• "How to List the Files on a Tape (cpio)"

• "How to Retrieve All Files From a Tape (cpio)"

• "How to Retrieve Specific Files From a Tape (cpio)"

• "How to Copy Files to a Remote Tape Drive (tar and dd)"

• "How to Extract Files From a Remote Tape Drive"

• "How to Copy Files to a Single Formatted Diskette (tar)"

• "How to List the Files on a Diskette (tar)"

• "How to Retrieve Files From a Diskette (tar)"

• "How to Archive Files to Multiple Diskettes"

• "How to Create an Archive for Older SunOS Releases"

• "How to Retrieve bar Files From a Diskette"

Commands for Copying File Systems

When you need to back up and restore complete file systems, use the ufsdump and ufsrestore commands described in Chapter 36, The ufsdump and ufsrestore Commands (Reference). When you want to copy or move individual files, portions of file systems, or complete file systems, you can use the procedures described in this chapter as an alternative to ufsdump and ufsrestore.

Table 37-1 describes when to use the various backup commands.

Do not restore files in the /tmp directory even temporarily. The /tmp directory is usually mounted as a TMPFS file system and it does not support UFS file system attributes such as ACLs.

Table 37-2 describe various backup and restore commands.

The following sections describe the advantages and disadvantages of each method and provide examples of how to use the commands.

Copying File Systems to Disk

Two commands are used to copy file systems to disk:

• volcopy

• dd

The next section describes how to use the dd command to copy file systems to disk.

Making a Literal File System Copy

The dd command makes a literal (block) copy of a complete UFS file system to another file system or to a tape. By default, the dd command copies its standard input to its standard output.

Do not use the dd command with variable-length tape drives.

You can specify a device name in place of the standard input or the standard output or both. In this example, contents of the diskette are copied to a file in the /tmp directory:

$ dd < /floppy/floppy0 > /tmp/output.file
2400+0 records in
2400+0 records out

The dd command reports on the number of blocks it reads and writes. The number after the + is a count of the partial blocks that were copied.

The dd command syntax is different from most other commands. Options are specified as keyword=value pairs, where keyword is the option you want to set and value is the argument for that option. For example, you can replace the standard input and output with this syntax:

$ dd if=input-file of=output-file

For example, to use the keyword=value pairs instead of the redirect symbols in the previous example, you would type:

$ dd if=/floppy/floppy0 of=/tmp/output.file

How to Clone a Disk (dd)

1. Make sure the source and destination disks have the same disk geometry.

2. Become superuser.

3. Create the /reconfigure file on the system with the master disk so that it will recognize the clone disk once it is rebooted.

4. Shut down the system.

   # init 0

5. Attach the clone disk to the system.

6. Boot the system.

   ok boot

7. Use the dd command to copy the master disk to the clone disk.

   # dd if=/dev/dsk/device-name of=/dev/dsk/device-name bs=blocksize

   if=/dev/dsk/device-name	Represents the master disk device as the input device.
   of=/dev/dsk/device-name	Represents the clone disk device as the output device.
   bs=blocksize	Block size.

8. Check the new file system.

   # fsck /dev/rdsk/device-name

9. Mount the clone disk's root (/) file system.

   # mount /dev/dsk/device-name /mnt

10. Edit the clone disk's /etc/vfstab to reference the correct device names.

11. Unmount the clone disk's root (/) file system.

    # umount /mnt

12. Shut down the system.

    # init 0

13. Boot from the clone disk to single-user mode.

    # boot diskn -s

14. Unconfigure the clone disk.

    # sys-unconfig

    The system is shut down after it is unconfigured.

15. Boot from the clone disk again and provide its system information, such as host name, time zone, etc.

    # boot diskn

16. Log in as superuser to verify the system information once the system is booted.

    hostname console login:

Example--Cloning a Disk (dd)

# init 0
ok boot
# dd if=/dev/dsk/c0t0d0s2 of=/dev/dsk/c0t2d0s2bs=100k
# fsck /dev/rdsk/c0t2d0s2
# mount /dev/dsk/c0t2d0s2 /mnt 
# cd /mnt/etc
# vi vfstab
(Modify entries for the new disk)
# cd /
# umount /mnt
# init 0
# boot disk2 -s
# sys-unconfig
# boot disk2

Copying Directories Between File Systems using the cpio Command

You can use the cpio (copy in and out) command to copy individual files, groups of files, or complete file systems. This section describes how to use the cpio command to copy complete file systems.

The cpio command is an archiving program that takes a list of files and copies them into a single, large output file. It inserts headers between the individual files to facilitate recovery. You can use the cpio command to copy complete file systems to another slice, another system, or to a media device such as tape or diskette.

Because the cpio command recognizes end-of-media and prompts you to insert another volume, it is the most effective command (other than ufsdump) to use to create archives that require multiple tapes or diskettes.

During cpio operations, you frequently use commands like ls and find to list and select the files you want to copy and then pipe the output to the cpio command.

How to Copy Directories Between File Systems (cpio)

1. Become superuser.

2. Change to the appropriate directory.

   # cd /filesystem1

3. Copy the directory tree using a combination of the find and cpio commands.

   # find . -print -depth | cpio -pdmu /filesystem2

   .	Starts in the current working directory.
   -print	Prints the file names.
   -depth	Descends the directory hierarchy and prints file names on the way back up.
   -p	Creates a list of files.
   -d	Creates directories as needed.
   -m	Sets the correct modification times on directories.

   The files from the directory name you specify are copied, and symbolic links are preserved.

   You may also specify the -u option. This option forces an unconditional copy. Otherwise older files will not replace newer files. This may be useful if an exact copy of a directory is desired, and some of the files being copied may already exist in the target directory.

4. If appropriate, remove the source directory.

   # rm -rf /filesystem1

5. Verify the copy was successful by displaying the destination directory contents.

   # cd filesystem2 # ls

Example--Copying Directories Between File Systems (cpio)

# cd /data1
# find . -print -depth | cpio -pdm /data2
19013 blocks
# cd /data2
# ls
# rm -rf /data1
# cd filesystem2
# ls

See cpio(1) for more information.

Copying Files and File Systems to Tape

The pax, tar, and cpio commands can be used to copy files and file systems to tape. The command you choose depends on how much flexibility and precision you require for the copy. Because all three commands use the raw device, you do not need to format or make a file system on tapes before you use them.

The tape drive and device name you use depend on the hardware and configuration for each system. See "Choosing Which Media to Use" for more information about tape drives and device names.

Copying Files to Tape With tar

Things you should know before copying files to tape with the tar command:

• Copying files to a tape using the -c option to tar destroys any files already on the tape.

• You can use filename substitution wildcards (? and *) as part of the file names you specify when copying files. For example, to copy all documents with a .doc suffix, type *.doc as the file name argument.

• You cannot use filename substitution wildcards for extracting files from a tar archive.

How to Copy Files to a Tape (tar)

1. Change to the directory that contains the files you want to copy.

2. Insert a write-enabled tape into the tape drive.

3. Copy the files to tape with the tar command.

   $ tar cvf /dev/rmt/n filename ...

   c	Indicates you want to create an archive.
   v	Displays the name of each file as it is archived.
   f /dev/rmt/n	Indicates that the archive should be written to the specified device or file.
   filename ...	Indicates the files you want to copy.

   The file names you specify are copied to the tape, overwriting any existing files on the tape.

4. Remove the tape from the drive and write the names of the files on the tape label.

5. Verify that the files copied are on the tape using the tar command with the t option, which displays the tape's contents. See "How to List the Files on a Tape (tar)" for more information on listing files on a tar tape.

   $ tar tvf /dev/rmt/n

Example--Copying Files to a Tape (tar)

In this example, three files are copied to a tape in tape drive 0.

$ cd /export/home/kryten
$ ls reports
reportA reportB reportC
$ tar cvf /dev/rmt/0 reports
a reports/ 0 tape blocks
a reports/reportA 2 tape blocks
a reports/reportB 5 tape blocks
a reports/reportC 6 tape blocks
$ tar tvf /dev/rmt/n 

How to List the Files on a Tape (tar)

1. Insert a tape into the tape drive.

2. Display the tape contents with the tar command.

   $ tar tvf /dev/rmt/n

   t	Lists the table of contents for the files on the tape.
   v	Used with the t option, and provides detailed information about the files on the tape.
   f /dev/rmt/n	Indicates the tape device.

Example--Listing the Files on a Tape (tar)

In this example, the table of contents for the tape in drive 0 contains three files.

$ tar tvf /dev/rmt/0
drwxr-xr-x 101/10       0 Nov  6 16:31 1996 reports/
-rw-r--r-- 101/10       0 Nov  6 16:31 1996 reports/reportA
-rw-r--r-- 101/10       0 Nov  6 16:31 1996 reports/reportB
-rw-r--r-- 101/10       0 Nov  6 16:31 1996 reports/reportC

How to Retrieve Files From a Tape (tar)

1. Change to the directory where you want to put the files.

2. Insert the tape into the tape drive.

3. Retrieve files from the tape using the tar command.

   $ tar xvf /dev/rmt/n filename filename

   x	Indicates that files should be extracted from the specified archive file. All of the files on the tape in the specified drive are copied to the current directory.
   v	Displays the name of each file as it is archived.
   f /dev/rmt/n	Indicates the tape device containing the archive.

4. Verify the files are copied by listing the contents of the current directory.

   $ ls -l

Example--Retrieving the Files on a Tape (tar)

In this example, all files are copied from the tape in drive 0.

$ cd /var/tmp
$ tar xvf /dev/rmt/0
x reports/, 0 bytes, 0 tape blocks
x reports/reportA, 0 bytes, 0 tape blocks
x reports/reportB, 0 bytes, 0 tape blocks
x reports/reportC, 0 bytes, 0 tape blocks
x reports/reportD, 0 bytes, 0 tape blocks
ls -l

The names of the files extracted from the tape must exactly match the names of the files stored on the archive. If you have any doubts about the names or paths of the files, first list the files on the tape. See "How to List the Files on a Tape (tar)" for instructions.

See tar(1) for more information.

Copying Files to a Tape With pax

This section describes how to copy files with the pax command.

How to Copy Files to a Tape (pax)

1. Change to the directory that contains the files you want to copy.

2. Insert a write-enabled tape into the tape drive.

3. Copy the files to tape with the pax command.

   $ pax -w -f /dev/rmt/0 .

   -w	Copies the current directory contents to tape.
   -f /dev/rmt/0	Identifies the tape drive.

4. Verify the files are copied to tape by using the pax -l command.

   $ pax -l -f /dev/rmt/0

5. Remove the tape from the drive and write the names of the files on the tape label.

Example--Copying Files to a Tape (pax)

$ pax -w -f /dev/rmt/0 .
$ pax -l -f /dev/rmt/0
filea fileb filec

See pax(1) for more information.

How to Copy All Files in a Directory to a Tape (cpio)

1. Insert a tape that is not write-protected into the tape drive.

2. Copy files to a tape using the ls and cpio commands.

   $ ls | cpio -oc > /dev/rmt/n

   ls	Provides the cpio command with a list of file names.
   cpio -oc	Specifies that cpio should operate in copy-out mode (-o) and write header information in ASCII character format (-c). This ensures portability to other vendor systems.
   > /dev/rmt/n	Specifies the output file.

   All of the files in the directory are copied to the tape in the drive you specify, overwriting any existing files on the tape. The total number of blocks copied is displayed.

3. Verify the files are copied to tape by using the following cpio command.

   $ cpio -civt < /tmp/cpio.file

4. Remove the tape from the drive and write the names of the files on the tape label.

Example--Copying All Files in a Directory to a Tape (cpio)

In this example, all of the files in the directory /export/home/kryten are copied to the tape in tape drive 0.

$ cd /export/home/kryten
$ ls | cpio -oc > /dev/rmt/0
8 blocks
$ cpio -civt < /tmp/cpio.file
drwxr-xr-x  2 kryten  users    0   Oct 24 11:05 1996, letters
drwxr-xr-x  2 kryten  users    0   Oct 24 11:05 1996, memos
drwxr-xr-x  2 kryten  users    0   Nov  8 14:14 1996, reports
8 blocks
$

How to List the Files on a Tape (cpio)

Listing the table of contents takes as long as it does to read the archive file because the cpio command must process the entire archive.

1. Insert a tape into the tape drive.

2. List the files on tape using the cpio command.

   $ cpio -civt < /dev/rmt/n

   -c	Specifies that cpio should read files in ASCII character format.
   -i	Specifies that cpio should operate in copy-in mode (even though its only listing files at this point).
   -v	Displays the output in a format similar to the output from the ls -l command.
   -t	Lists the table of contents for the files on the tape in the tape drive you specify.
   < /dev/rmt/n	Specifies the input file of an existing cpio archive.

Example--Listing the Files on a Tape (cpio)

In this example, the table of contents for the tape in drive 0 contains three files.

$ cpio -civt < /dev/rmt/0
drwxr-xr-x  2 rimmer users 0  Oct 28 09:17 1996, answers
drwxr-xr-x  2 rimmer users 0  Oct 28 09:17 1996, sc.directives
drwxr-xr-x  2 rimmer users 0  Oct 28 09:17 1996, tests
8 blocks

How to Retrieve All Files From a Tape (cpio)

If the archive was created using relative path names, the input files are built as a directory within the current directory when you retrieve the files. If, however, the archive was created with absolute path names, the same absolute paths are used to recreate the file on your system.

Using absolute path names can be dangerous because you may overwrite existing files on your system.

1. Change to the directory where you want to put the files.

2. Insert the tape into the tape drive.

3. Copy all files from the tape to the current directory using the cpio command.

   $ cpio -icvd < /dev/rmt/n

   -i	Reads in the contents of the tape.
   -c	Specifies that cpio should read files in ASCII character format.
   -v	Displays the output in a format similar to the output from the ls -l command.
   -d	Create directories as needed.
   < /dev/rmt/n	Specifies the output file.

4. Verify the files are copied by listing the contents of the current directory.

   $ ls -l

Example--Retrieving All Files From a Tape (cpio)

In this example, all files are copied from the tape in drive 0.

$ cd /var/tmp
cpio -icvd < /dev/rmt/0
answers sc.directives tests
8 blocks
$ ls -l

How to Retrieve Specific Files From a Tape (cpio)

1. Change to the directory where you want to put the files.

2. Insert the tape into the tape drive.

3. Retrieve a subset of files from a tape using the cpio command.

   $ cpio -icv "*file" < /dev/rmt/n

   -i	Reads in the contents of the tape.
   -c	Specifies that cpio should read headers in ASCII character format.
   -v	Displays the output in a format similar to the output from the ls -l command.
   "*file"	Specifies that all of the files that match the pattern are copied to the current directory. You can specify multiple patterns, but each must be enclosed in double quotation marks.
   < /dev/rmt/n	Specifies the input file.

4. Verify the files are copied by listing the contents of the current directory.

   $ ls -l

Example--Retrieving Specified Files From a Tape (cpio)

In this example, all files with suffix chapter are copied from tape drive 0.

$ cd /home/smith/Book
$ cpio -icv "*chapter" < /dev/rmt/0
Boot.chapter Directory.chapter Install.chapter Intro.chapter
31 blocks
$ ls -l

See cpio(1) for more information.

How to Copy Files to a Remote Tape Drive (tar and dd)

1. The following prerequisites must be met to use a remote tape drive:

   • The local hostname (and optionally the username of the user doing the copy) must appear in the remote system's /etc/hosts.equiv file, or the user doing the copy must have his or her home directory accessible on the remote machine, and have the local machine name in $HOME/.rhosts. See hosts.equiv(4) for more information.

   • An entry for the remote system must be in the local system's /etc/inet/hosts file or in the name service hosts file.

2. To test whether or not you have the appropriate permission to execute a remote command, try the following.

   $ rsh remotehost echo test

   If "test" is echoed back to you, you have permission to execute remote commands. If "Permission denied" is echoed, check your setup as described in step 1 above.

3. To copy files to a remote tape drive use the tar and dd commands.

   $ tar cf - files | rsh remotehost dd of=/dev/rmt/n obs=blocksize

   tar cf	Creates a tape archive and specifies the tape device.
   - (Hyphen)	Represents a placeholder for the tape device.
   files	Identifies files to be copied.
   | rsh remotehost	Pipe tar command to a remote shell to copy the files.
   dd of=/dev/rmt/n	Represents the output device.
   obs=blocksize	Represents the blocking factor.

4. Remove the tape from the drive and write the names of the files on the tape label.

Example--Copying Files to a Remote Tape Drive (tar and dd)

# tar cvf - * | rsh mercury dd of=/dev/rmt/0 bs=126b
a answers/ 0 tape blocks
a answers/test129 1 tape blocks
a sc.directives/ 0 tape blocks
a sc.directives/sc.190089 1 tape blocks
a tests/ 0 tape blocks
a tests/test131 1 tape blocks
0+2 records in
0+2 records out

How to Extract Files From a Remote Tape Drive

1. Change to a temporary directory.

   $ cd /var/tmp

2. To extract files to a remote tape drive use the tar and dd commands.

   $ rsh remotehost dd if=/dev/rmt/n | tar xvBpf -

   rsh remotehost	Is a remote shell that is started to extract the files from the tape device using the dd command.
   dd if=/dev/rmt/n	Indicates the input device.
   | tar xvBpf -	Pipes the output of the dd command to the tar command used to restored the files.

3. Verify that the files have been extracted.

   $ ls -l /var/tmp

Example--Extracting Files From a Remote Tape Drive

$ rsh mercury dd if=/dev/rmt/0 | tar xvBpf -
x answers/, 0 bytes, 0 tape blocks
x answers/test129, 48 bytes, 1 tape blocks
20+0 records in
20+0 records out
x sc.directives/, 0 bytes, 0 tape blocks
x sc.directives/sc.190089, 77 bytes, 1 tape blocks
x tests/, 0 bytes, 0 tape blocks
x tests/test131, 84 bytes, 1 tape blocks
$ ls -l /var/tmp

Copying Files and File Systems to Diskette

Before you can copy files or file systems to diskette, you must format the diskette. See Chapter 13, Formatting and Using Diskettes From the Command Line (Tasks)for information on how to format a diskette.

Use the tar command to copy UFS files to a single formatted diskette.

Use the cpio command if you need to copy UFS files to multiple formatted diskettes. cpio recognizes end-of-media and prompts you to insert the next volume.

Using the cpio command to copy UFS files to multiple formatted diskettes is not a straightforward procedure because of Volume Management.

Use double-sided high-density 3.5-inch diskettes (diskettes are marked "DS, HD").

Things You Should Know When Copying Files to Diskettes

• If the diskette contains a mounted file system, you must unmount the file system before running tar. You can unmount the file system using the umount command, or you can unmount the file system and format the diskette using the fdformat -U command.

• Copying files to a formatted diskette using the -c option of tar destroys any files already on the diskette.

• Reformatting a diskette destroys any files or archives that were already on the diskette.

How to Copy Files to a Single Formatted Diskette (tar)

1. Change to the directory that contains the files you want to copy.

2. Insert a formatted diskette that is not write-protected into the drive.

3. Make the diskette available using the volcheck command.

4. Unmount any file system on the diskette and reformat it.

   $ fdformat -U/vol/dev/aliases/floppy0

5. Copy the files to diskette using the tar command.

   $ tar cvf /vol/dev/rdiskette0/unlabeled filename ...

   The file names you specify are copied to the diskette, overwriting any existing files on the diskette.

6. Verify that the files copied are on the diskette using the tar command with the -t option, which displays the diskette's contents. See "How to List the Files on a Diskette (tar)" for more information on listing files.

   $ tar tvf /vol/dev/rdiskette0/unlabeled

7. Remove the diskette from the drive.

8. Write the names of the files on the diskette label.

Example--Copying Files to a Single Formatted Diskette (tar)

In this example, two files are copied to a diskette:

$ cd /home/smith
$ ls evaluation*
evaluation.doc   evaluation.doc.backup
$ tar cvf /vol/dev/rdiskette0/unlabeled evaluation*
a evaluation.doc 86 blocks
a evaluation.doc.backup 84 blocks
$ tar tvf /vol/dev/rdiskette0/unlabeled

How to List the Files on a Diskette (tar)

1. Insert a diskette into the drive.

2. Run volcheck to make the diskette available.

3. Use the tar command to list the files on a diskette.

   $ tar tvf /vol/dev/rdiskette0/unlabeled

Example--Listing the Files on a Diskette (tar)

In this example, the table of contents for the diskette shows two files:

$ tar tvf /vol/dev/rdiskette0/unlabeled
rw-rw-rw-6693/10  44032 Oct 23 14:54 1996 evaluation.doc
rw-rw-rw-6693/10  43008 Oct 23 14:47 1996 evaluation.doc.backup
$

See tar(1) for more information.

If you need a multiple-volume interchange utility, use the cpio command. The tar command is only a single-volume utility.

How to Retrieve Files From a Diskette (tar)

1. Change to the directory where you want to put the files.

2. Insert the diskette into the drive.

3. Run volcheck to make the diskette available.

4. Use the tar command to retrieve files from a diskette.

   $ tar xvf /vol/dev/rdiskette0/unlabeled

   All of the files on the diskette are copied to the current directory.

5. Verify the files have been retrieved by listing the contents of the current directory.

   $ ls -l

6. Remove the diskette from the drive.

Examples--Retrieving Files From a Diskette (tar)

In this example, all files are copied from the diskette:

$  /home/smith/Evaluations
$ tar xvf /vol/dev/rdiskette0/unlabeled
x evaluation.doc, 44032 bytes, 86 tape blocks
x evaluation.doc.backup, 43008 bytes, 84 tape blocks
$ ls -l

Use the tar command to retrieve individual files from a diskette.

$ tar xvf /vol/dev/rdiskette0/unlabeled filename ...

The file names you specify are extracted from the diskette and placed in the current working directory.

How to Archive Files to Multiple Diskettes

If you are copying large files or file systems onto diskettes, you want to be prompted to replace a full diskette with another formatted diskette. The cpio command provides this capability. The cpio commands you use are the same as you would use to copy files to tape, except you would specify /vol/dev/aliases/floppy0 as the device instead of the tape device name. See "How to Copy All Files in a Directory to a Tape (cpio)" for information on how to use cpio.

Copying Files With a Different Header Format

Archives created with the SunOS 5.x cpio command may not be compatible with older SunOS releases. The cpio command allows you to create archives that can be read with several other formats. You specify these formats using the -H option and one of these arguments:

• crc or CRC - ASCII header with checksum

• ustar or USTAR - IEEE/P1003 Data Interchange

• tar or TAR - tar header and format

• odc - ASCII header with small device numbers

• bar - bar header and format

The syntax for using the header options is:

cpio -o -H header-option < file-list > output-archive

How to Create an Archive for Older SunOS Releases

Use the cpio command to create the archive.

$ cpio -oH odc < file-list > /dev/rmt/n

The -H values have the same meaning for input as they do for output. If the archive was created using the -H option, you must use the same option when the archive is read back in or the cpio command will fail, as shown below.

Example--Creating an Archive for Older SunOS Releases

$ find . -print | cpio -oH tar > /tmp/test
 
113 blocks
$ cpio -iH bar < /tmp/test
cpio: Invalid header "bar" specified
USAGE:
        cpio -i[bcdfkmrstuvBSV6] [-C size] [-E file] [-H hdr]
            [-I file [-M msg]] [-R id] [patterns]
        cpio -o[acvABLV] [-C size] [-H hdr] [-O file [-M msg]]
        cpio -p[adlmuvLV] [-R id] directory

When you create an archive using different options, always write the command syntax on the media label along with the names of the files or file system on the archive.

If you do not know which cpio options were used when an archive was created, all you can do is experiment with different combinations of the options to see which ones allow the archive to be read.

See cpio(1) for a complete list of options.

Retrieving Files Created With the bar Command

To retrieve files from diskettes that were archived using the SunOS 4.x bar command, use the -H bar option to cpio.

You can only use the -H bar option with -i to retrieve files. You cannot create files with the bar header option.

How to Retrieve bar Files From a Diskette

1. Change to the directory where you want to put the files.

2. Use the cpio command to retrieve bar files from a diskette.

   All the files on the diskette are copied to the current directory.

   $ cpio -ivH bar < /vol/dev/rdiskette/unlabeled

Chapter 38 Managing Tape Drives (Tasks)

This chapter describes how to manage tape drives.

This is a list of the step-by-step instructions in this chapter.

• "How to Determine the Type of a Tape Drive"

• "How to Show the Status of a Magnetic Tape Drive"

• "How to Retension a Magnetic Tape Cartridge"

• "How to Rewind a Magnetic Tape Cartridge"

Choosing Which Media to Use

You typically back up Solaris 2.5 systems using:

• 1/2-inch reel tape

• 1/4-inch streaming cartridge tape

• 8-mm cartridge tape

• 4-mm cartridge tape (DAT)

You can perform backups using diskettes, but this is time-consuming and cumbersome.

The media you choose depends on the availability of the equipment that supports it and of the media (usually tape) that you use to store the files. Although you must do the backup from a local system, you can write the files to a remote device.

Table 38-1 shows typical media used for backing up file systems and shows the length (or storage capacity) for each.

Capacity for 4-mm cartridge tapes depends on the type of drive and the data being written to the tape.

Backup Device Names

You specify a tape or diskette drive to use for backup by supplying a logical device name. This name points to the subdirectory containing the "raw" device file and includes the logical unit number of the drive. Tape drive naming conventions use a logical, not a physical, device name. Table 38-2 shows this naming scheme.

The drive writes at its "preferred" density, which usually means the highest density it supports. Most SCSI drives can automatically sense the density or format on the tape and read it accordingly.

Tape drives fall into two categories based on controller type:

• Xylogics^TM 472 for 1/2-inch rack-mounted (top-loaded) reel-to-reel drives (see Figure 38-1)

• SCSI for 1/4-inch cartridge, 1/2-inch front-loaded reel-to-reel, and 4-mm or 8-mm helical scan drives

Within the /dev/rmt subdirectory is a set of tape device files that support different output densities.

In general, you specify a tape drive device as shown in Figure 38-1.

Figure 38-1 Tape Drive Device Names

You can have both SCSI and non-SCSI tape drives on the same system.

• A SCSI controller can have a maximum of seven SCSI tape drives.

• A non-SCSI controller can have a maximum of four tape drives.

• For each drive number (X), the density character depends on the controller and drive type as described in the following paragraphs.

Table 38-3 shows the device abbreviation for different tape controllers/units and media. Note that the first character in the device abbreviation for drive number does not have to be 0 as shown, but could be 1, 2, or 3, and so on, depending on how many tape drives are attached to the system.

Rack-Mounted Non-SCSI 1/2-Inch Reel Drives

For 1/2-inch rack-mounted tape drives with either a Tapemaster or Xylogics 472 controller, substitute the density from Table 38-4 for the A variable in the device name (/dev/rmt/XA).

If you omit the density character, the tape is usually written at its highest density, not compressed.

SCSI 1/4-Inch Cartridge and 1/2-Inch Front-Loaded Reel Drives

For SCSI 1/4-inch cartridge and 1/2-inch front-loaded reel drives, substitute the density from Table 38-5for the A variable in the device name (/dev/rmt/XA).

For 1/4-inch cartridges, density is specified by the format in which the data is written: the QIC format. The QIC-11 and QIC-24 format write approximately 1000 bytes per inch on each track. The density for QIC-150 is somewhat higher. The "preferred" density for a 60-Mbyte 1/4-inch cartridge drive is QIC-24 and for a 150-Mbyte 1/4-inch cartridge drive is QIC-150.

An 18-track drive can write only QIC-150; it cannot be switched to write QIC-24 or QIC-11. Format selection is only useful for drives that can write both QIC-24 and QIC-11.

Specifying the Default Density for a Tape Drive

Normally, you specify a tape drive by its logical unit number, which may run from 0 to n. Table 38-6 describes how to specify tape device names using default density settings.

By default, the drive writes at its "preferred" density, which is usually the highest density it supports. If you do not specify a tape device, the command writes to drive number 0 at the default density the device supports.

Specifying Different Densities for a Tape Drive

To transport a tape to a system whose tape drive supports only a certain density, specify a device name that writes at the desired density. Table 38-7 describes how to specify different densities for a tape drive.

The unit and density characters are shown in Figure 38-1.

Determining Tape Drive Types

You can use the status option with the mt command to get status information about the Xylogics 472 1/2-inch tape drive and the Exabyte EXB-8200 8-mm tape drive.

The mt command also reports information about these 1/4-inch tape drives:

• Xylogics 472

• Exabyte EXB-8200

• Sysgen (QIC-24)

• Emulex MT-02 (QIC-24)

• Archive QIC-150

• Wangtek QIC-150

How to Determine the Type of a Tape Drive

1. Load a tape into the drive you want information about.

2. Display tape drive information with the mt command.

   # mt -f /dev/rmt/n status

3. Repeat steps 1-2, substituting tape drive numbers 1, 2, 3, and so on to display information about all available tape drives.

Example--Determining the Type of a Tape Drive

This example shows status for a QIC-150 tape drive (/dev/rmt/0) and an Exabyte tape drive (/dev/rmt/1).

$ mt -f /dev/rmt/0 status
Archive QIC-150 tape drive:
   sense key(0x0)= No Additional Sense   residual= 0   retries= 0
   file no= 0   block no= 0
$ mt -f /dev/rmt/1 status
Exabyte EXB-8200 8mm tape drive:
sense key(0x0)= NO Additional Sense residual= 0  retries= 0
file no= 0   block no= 0

Here is an quick way to poll a system and locate all tape drives. In this example, the tape drive is at 0.

$ for drive in 0 1 2 3 4 5 6 7
> do
> mt -f /dev/rmt/$drive status
> done
Archive QIC-150 tape drive:
   sense key(0x0)= No Additional Sense   residual= 0   retries= 0
   file no= 0   block no= 0
/dev/rmt/1: No such file or directory
/dev/rmt/2: No such file or directory
/dev/rmt/3: No such file or directory
/dev/rmt/4: No such file or directory
/dev/rmt/5: No such file or directory
/dev/rmt/6: No such file or directory
/dev/rmt/7: No such file or directory
$ 

How to Show the Status of a Magnetic Tape Drive

To display tape drive status information, use the mt command.

$ mt -f /dev/rmt/n status

Status for the tape drive you specify is displayed.

Examples--Showing the Status of a Magnetic Tape Drive

In the following example, there is no tape in drive /dev/rmt/1.

$ mt -f /dev/rmt/1 status
/dev/rmt/1: no tape loaded or drive offline
$

In this example, the status is shown for the tape in drive /dev/rmt/1.

$ mt -f /dev/rmt/1 status
Archive QIC-150 tape drive:
   sense key(0x6)= unit attention   residual= 0   retries= 0
   file no= 0   block no= 0
$

Handling Magnetic Tape Cartridges

If errors occur when reading a tape, retension the tape, clean the tape drive, and then try again.

How to Retension a Magnetic Tape Cartridge

Retension a magnetic tape cartridge with the mt command.

$ mt -f /dev/rmt/n retension
 

Example--How to Retension a Magnetic Tape Drive

In this example, the tape in drive /dev/rmt/1 is retensioned.

$ mt -f /dev/rmt/1 retension
$

Do not retension non-QIC tape drives.

How to Rewind a Magnetic Tape Cartridge

To rewind a magnetic tape cartridge, use the mt command.

$ mt -f /dev/rmt/n rewind

Example--Rewinding a Magnetic Tape Cartridge

In this example, the tape in drive /dev/rmt/1 is rewound.

$ mt -f /dev/rmt/1 rewind
$

Guidelines for Drive Maintenance and Media Handling

A backup tape that cannot be read is useless. It is a good idea to clean and check your tape drives periodically to ensure correct operation. See your hardware manuals for instructions on procedures for cleaning a tape drive. You can check your tape hardware by:

• Copying some files to the tape, reading them back, and then comparing the original with the copy.

• Or, you could use the -v option of the ufsdump command to verify the contents of the media with the source file system. The file system must be unmounted or completely idle for the -v option to be effective.

Be aware that hardware can fail in ways that the system does not report.

Always label your tapes after a backup. If you have planned a backup strategy similar to those suggested in Chapter 33, Backing Up and Restoring File Systems (Overview), you should indicate on the label "Tape A," "Tape B," and so forth. This label should never change. Every time you do a backup, make another tape label containing the backup date, the name of the machine and file system backed up, backup level, the tape number (1 of n, if it spans multiple volumes), plus any information specific to your site. Store your tapes in a dust-free safe location, away from magnetic equipment. Some sites store archived tapes in fireproof cabinets at remote locations.

You should create and maintain a log that tracks which media (tape volume) stores each job (backup) and the location of each backed-up file.