Backing Up Existing File Systems

You should back up your existing file systems before you upgrade the software. Backing up your existing file system is especially important if the following conditions exist:

• You are currently using a version 1 superblock with Sun StorageTek QFS 4U0 system and you want to reinitialize your file systems with a version 2A superblock. See How to Reinitialize and Restore the File System for details about how to reinitialize the file systems and restore your data.

• You suspect that your current qfsdump file is incorrect or outdated.

The following sections explain the differences between the superblock versions and present the procedure for backing up your file systems.

Backing Up Using the Version 1, Version 2, and Version 2A Superblocks

By default, Sun QFS and SAM-QFS 5.0 and later releases create new file systems that have a version 2A superblock. This enables the following features:

• Large host table (larger than 16 kbytes)

• Online grow using samadm eq-add or samu add command

A version 2A file system is not compatible with earlier product versions. For example, you cannot mount a version 2A file system on SAM-QFS 4.6. If you need to create a file system that you can mount on earlier releases of the product, use the sammkfs -P command.

To support a large host table or online grow on an existing version 2 file system, use the samfsck -u 2A file-system command to upgrade the file system to version 2A.

How to Back Up the File System (Sun QFS Configurations)

Follow these steps for each file system in your environment.

1. Become superuser from a console connection.

   If you have not already logged in as root, do so now.

2. Boot the system in single-user mode.

   # boot -s

3. Mount the file system.

   For example:

   # mount /qfs1

4. Use the qfsdump command to back up the file data and metadata of the file system to a location outside the existing file system.

   The qfsdump command dumps file names, inode information, and file data. The destination of the qfsdumpoutput (generally a file) must be at least as large as the file system that you are backing up. The destination location (disk or tape) must have enough space to hold the amount of file data and metadata that you are dumping. For more information about using the qfsdumpcommand, see Setting Up Dump Files or see the qfsdump(1M) man page.

   For example, if you have a file system named qfs1 (mounted at /qfs1) that you want to back up, your choices are shown in the following examples.

Example 10-3 Writing the qfsdump Output to a Tape Device

The following example shows how to write to a tape in device /dev/rmt/1cbn.

# cd /qfs1
# qfsdump -f /dev/rmt/1cbn

Example 10-4 Writing the qfsdump Output to a File in a UNIX File System (UFS)

The following example shows how to write to a file in a UFS.

# cd /qfs1
# qfsdump -f /save/qfs/qfs1.bak

Example 10-5 Initializing a New Sun QFS File System and Performing the qfsrestore Command Directly in That New File System

This alternative is applicable only if you have already installed the Sun QFS 5.0 software somewhere in your environment.

For example, assume that you want to write the dump file into a second file system called qfs2 (mounted at /qfs2) and that you initialized the qfs2 file system using the 5.0 software. The following example shows how to accomplish this using commands.

# mount /qfs2
# cd /qfs1
# qfsdump -f - | (cd /qfs2; qfsrestore -f -)

How to Back Up a File System (SAM-QFS Configurations)

1. Become superuser from a console connection.

   If you have not already logged in as root, do so now.

2. Make sure that all files are archived.

   The following example assumes that sam1 is the mount point of the file system. You can complete this step by entering a command similar to the following:

   # sfind /sam1 ! -type d ! -archived > /tmp/notarchived.list

   This command finds all files that are not archived and sends the output to a file. Depending on the size of your file system, this command can take a long time to complete.

3. Examine this command's output.

   • If you want any of these unarchived files to appear in the dump file, archive them now.

   • Use the -u option to the samfsdump command to dump unarchived data if you suspect that some files have not yet been archived. The -u option can create very large dump files, however, so consider space limitations when using this option.

4. Use the samfsdump command to back up each file system's metadata to a location outside the existing file system.

   See Creating Archive Recovery Points for information about recovery points.

   The samfsdump command dumps file names and inode information, not data. For more information, see the samfsdump(1M) man page.

Example Of Using the samfsdump Command

This example assumes that you have a file system mounted at /sam1 that you want to back up to samfs1.dump, which exists outside of the current file systems.

# cd /sam1
# samfsdump -f /csd_dump_dir/samfs1.dump