Archive Set Copy Parameters

The archive set copy parameters define how each archive set is archived: the data files, directories, symbolic links, the index of segmented files, and archive media information.

The archive set copy parameters section of the archiver.cmd file begins with the params directive and ends with the endparams directive.

The following example shows the format for copy parameters for an archive set.

params
archive-set-name.copy-number[R] [-param1 -param2 ...]
.
.
.
endparams

Table 12-3 Arguments for the Archive Set Copy Parameters

Argument	Definition
archive-set-name	A site-defined name for the archive set. A best practice is to define a name that identifies the common characteristics of the files belonging to the archive set. The name has the following requirements: Maximum of 29 characters Uppercase and lowercase alphabetic characters, numbers 0-9, and the underscore character (`_`). No other special characters or spaces are allowed. The first character must be a letter.
copy-number	An integer that defines the archive copy number: `1`, `2`, `3`, or `4`.
`R`	Specifies that the parameters being defined are for re-archived copies of this archive set. For example, you can use the `R` and specify VSNs in the `-`param1 argument to direct re-archived copies to specific volumes.
`-param1` `-param`2	One or more parameters such as maximum size, buffer size, number of drives, and so on. The following subsections describe the parameters than can be specified between the `params` and `endparams` directives.

To set default directives for all archive sets, specify directives for the archive set allsets archive set. The allsets directives must precede the directives for archive set copies because parameters set for individual archive set copies override parameters set for the allsets directive. For more information about the allsets archive set, see archiver.cmd(4) in Sun QFS and Sun Storage Archive Manager Reference Manual.

You can specify archive set copy parameters by editing the archiver.cmd file as described in the following sections or by using the SAM-QFS Manager software. For more information, see the SAM-QFS Manager online help.

The following sections describe all archive set processing parameters with the exception of disk archiving parameters. For information about disk archiving parameters, see About Disk Archiving.

Controlling the Size of Archive Files: `-archmax` Parameter

The -archmax parameter sets the maximum file size for an archive set. This parameter has the following format:

-archmax target-size

This parameter is very similar to the archmax global directive. For information about that directive and the values to enter for target-size, see Controlling the Size of Archive Files: -archmax Parameter.

Setting the Archiver Buffer Size: `-bufsize` Parameter

By default, a file being archived is stored in memory in a buffer of a default size for the media type before being written to archive media. Use the -bufsize directive to specify a buffer size. A custom size can improve performance. This parameter has the following format:

-bufsize=buffer-size

The default buffer size is 4, indicating that the actual buffer size is 4 multiplied by the dev_blksize value for the media type. Specify a number from 2 to 32. The dev_blksize value is specified in the defaults.conf file.

For more information about this file, see defaults.conf(4) in Sun QFS and Sun Storage Archive Manager Reference Manual.

Example 12-10 Buffer Size: -bufsize

myset.1 -bufsize=6

This parameter is similar to the bufsize=media buffer-size global directive. For more information about that directive, see Setting the Archiver Buffer Size: -bufsize Parameter.

Specifying the Number of Drives for an Archive Request: `-drivemax`, `-drivemin`, and `-drives`

By default, the archiver uses one media drive to archive the files of one archive set. When an archive set has many files or large files, using more than one drive is advantageous. In addition, if the drives in your automated library operate at different speeds, use of multiple drives can balance these variations and increase archiving efficiency. The drive directives have the following formats:

-drivemax max-size
-drivemin min-size
-drives number

Argument	Definition
max-size	The maximum amount of data to be archived using one drive.
min-size	The minimum amount of data to be archived using one drive. The default is the `-archmax` target-size value (if specified) or the default value for the media type. If you specify the `-drivemin` min-size directive, the SAM-QFS software uses multiple drives only when enough activity occurs to warrant it. As a guideline, set min-size to be large enough to cause the transfer time to be significantly longer than the cartridge change time (load, position, unload).
number	The number of drives to be used for archiving this archive set. The default is 1.

An archive request is evaluated against the parameters that are specified, as follows:

If an archive request is less than the value of min-size, only one drive is used to write an archive request.
If an archive request is larger than the value of min-size, the archive request is evaluated against min-size and the appropriate number of drives is scheduled up to the full number of drives specified.
If the value of min-size is 0, an attempt is made to split the archive request among the full number of drives specified.

When you use the -drives parameter, multiple drives are used only if data that is more than the value of min-size is to be archived. The number of drives to be used in parallel is the lesser of the following two values:

The size of the archive request divided by the value of min-size
The number of drives specified by the -drives parameter

Use the -drivemin and -drives parameters when you want to divide an archive request among drives but do not want to have all the drives busy with small archive requests. This situation can occur with very large files.

To set these parameters, consider file creation rates, the number of drives, the time it takes to load and unload drives, and drive transfer rates. For example, a site splits an archive set named bigfiles across five drives. This archive set could be split as shown in the following table.

Archive Set Size	Number of Drives
< 20 gigabytes	1
> 20 gigabytes to < 30 gigabytes	2
> 30 gigabytes to < 40 gigabytes	3
> 40 gigabytes to < 50 gigabytes	4
> 50 gigabytes	5

Example 12-11 Directives Used to Split an Archive Request Over Multiple Drives

The following example how to split the archive requests of 10 GB or more over five drives.

params
bigfiles.1 -drives 5 -drivemin 10G
endparams

In addition, the following line ensures that two drives are used to archive the files when the total size of the files in archive set huge_files.2 is equal to or greater than two times drivemin for the media.

huge_files.2 -drives 2

Maximizing Space on a Volume: `-fillvsns` Parameter

By default, the archiver selects a volume with enough space for all files when it writes an archive copy. This action results in volumes not being filled to capacity. When -fillvsns is specified, the archiver separates the archive request into smaller groups and can use different volumes.

Specifying Archive Buffer Locks: `-lock` Parameter

By default, a file is stored in a buffer before being written to archive media. If direct I/O is enabled, you can use the -lock parameter to lock this buffer. The -lock parameter indicates that the archiver must use locked buffers when making archive copies. If -lock is specified, the archiver sets file locks on the archive buffer in memory for the duration of the sam-arcopy operation. This action avoids paging of the buffer, and can improve performance.

This parameter has the following format:

-lock

Use the -lock parameter only on large systems with large amounts of memory. Insufficient memory can cause an out-of-memory condition.

The -lock parameter is effective only if direct I/O is enabled for the file. By default, -lock is not specified, and the file system sets locks on all direct I/O buffers, including those for archiving. For more information about enabling direct I/O, see setfa(1) in Sun QFS and Sun Storage Archive Manager Reference Manual, sam_setfa(3) in Sun QFS and Sun Storage Archive Manager Reference Manual, or -O forcedirectio option on mount_samfs(1M) in Sun QFS and Sun Storage Archive Manager Reference Manual.

This parameter is similar to the lock argument to the bufsize global directive. For more information about this topic, see Setting the Archiver Buffer Size: -bufsize Parameter.

Making Archive Copies of Offline Files: `-offline_copy` Parameter

A file is a candidate for being released after one archive copy is made. If the file is released and goes offline before any remaining archive copies are made, the archiver uses this parameter to determine the method use to make the other archive copies. When you specify the method, consider the number of drives available to the SAM-QFS system and the amount of disk cache available. This parameter has the following format:

-offline_copy method

method Value	Definition
`none`	Stages files as needed for each file before copying to the archive volume. Default.
`direct`	Copies files directly from the offline volume to the archive volume without using the cache. This method assumes that the source volume and the destination volume are different volumes and that two drives are available. Raise the value of the `stage_n_window` mount option to a value that is greater than its default of 256 kilobytes. For more information about mount options, see mount_samfs(1M) in Sun QFS and Sun Storage Archive Manager Reference Manual.
`stageahead`	Stages the next archive file while writing an archive file to its destination.
`stageall`	Stages all files to disk cache before archiving. This method uses one drive and assumes that room is available on disk cache for all files.

Specifying Recycling

Use the recycling process to reclaim space on archive volumes in use by expired archive images. By default, no recycling occurs. You must specify directives in both the archiver.cmd file and the recycler.cmd file. For more information, see Chapter 16, Configuring the Recycler.

Sorting Archive Files: `-sort` and `-rsort` Parameters

By default, files in an archive set are sorted by path before they are archived. You can specify that files are sorted by age, priority, or size, or not sorted (none). Only one sort method can be used per archive set.

You can use -rsort to reverse the order of sorting specified by method.

Example 12-12 Sorting Files in an Archive Set

The first example line sorts the archive set copy cardiac.2 by the age of the file, oldest to youngest. The second line forces the archive set copy catscans to be sorted by the size of the file, in reverse order, largest to smallest.

size.

cardiac.2 -sort age
catscans.3 -rsort size

Controlling Unarchiving

Unarchiving is the process by which archive entries for files or directories are deleted. A file is unarchived based on the time since it was last accessed. This distinction means data that is accessed frequently can be stored on fast media such as disk and infrequently accessed data can be stored on tape. By default, files are never unarchived.

Example 12-13 Directives to Control Unarchiving

This following example directives specify that the arset1 file remains on disk all the time, even if it is older than 60 days. The Copy 1 information is removed when the file has not been accessed for 60 days. After the Copy 1 information is removed, any access request is fulfilled by Copy 2 and is read from tape. The archiver makes a new Copy 1 on disk and the 60-day cycle starts again.

arset1 dir1
1 10m 60d
2 10m
3 10m
vsns
arset1.1 mo OPT00[0-9]
arset1.2 lt DLTA0[0-9]
arset1.3 lt DLTB0[0-9]

The example directives meet the requirements for both access and archiving in the following scenario.

A patient is in the hospital for four weeks. During this time, all the patient's files are on fast media and the data is being access frequently. This is Copy 1 (copy 1=mo). After two weeks, the patient is discharged from the hospital. The patient files are accessed less frequently and then not at all. When no data has been accessed for this patient 60 days, the Copy 1 entry in the inode is unarchived. Only Copy 2 and Copy 3 entries are available. The volume of fast media can now be recycled and used by current patients without having to increase the disk library. However, six months later, the patient returns to the hospital. The first access of the patient's file is from tape (Copy 2). To get the data on fast media, the archiver creates a new Copy 1 on disk, ready for new information.

Controlling How Archive Files Are Written: `-tapenonstop` Parameter

By default, the archiver writes a tape mark, an end of file (EOF) label, and two more tape marks between archive files. When the next archive file is started, the driver backs up to the position after the first tape mark, causing a loss of performance. The -tapenonstop parameter directs the archiver to write only the initial tape mark. In addition,the archiver enters the archive information at the end of the copy operation.

For more information about the -tapenonstop parameter, see archiver.cmd(4) in Sun QFS and Sun Storage Archive Manager Reference Manual.

Reserving Volumes: `-reserve` Parameter

By default, the archiver writes archive set copies to any volume specified by a regular expression as described in the volume associations section of the archiver.cmd file. However, if you require that an archive set volume contains files from only one archive set, you can reserve a volume for this purpose.

Note the following guidelines:

A site that uses reserved volumes incurs more cartridge loads and unloads.
A site that uses reserved volumes for file systems that have many directories of a few small files causes the archiver to write many small archive files to each reserved volume. These small archive files, each with its own tar header, slow performance.

The -reserve parameter specifies a volume for use by an archive set and gives it a unique identifier that ties the archive set to the volume. The volume identifier is not assigned to any other archive set copy, even if a regular expression matches it. The format for the -reserve parameter is as follows:

-reserve keyword

The value of keyword depends on the form you are using. You can specify one, two, or all three forms in combination.

Form	keyword	Reserved Name Examples	Notes
Archive Set	`set`	`users.1//` `{}Data.1//`
Owner	`dir`	`proj.1/p105/` `{}proj.1/p104/`	The `dir`, `user`, and `group` keywords, which are mutually exclusive, specify the owner component in the reserved name. The `dir` keyword uses the directory path component immediately following the path specification of the archive set definition.
	`user`	`users.1/user5/` `{}users.1/user4/`
	`group`	`data.1/engineering/`
File System	`fs`	`proj.1/p103/samfs1{}` `{}proj.1/p104/samfs1`	The `fs` keyword specifies the file system component in the reserved name.

Example 12-14 Reserving Volumes by Archive Set

The following example specifies that the allsets archive set reserves a volume for each archive set.

params
allsets -reserve set
endparams

Example 12-15 Reserved Volume Name

The following example specifies that the arset.1 archive set reserves a volume and the volume identifier is created from an archive set, a group, and the file system.

params
arset.1 -reserve set -reserve group -reserve fs
endparams

Information about reserved volumes is stored in the library catalog. The lines in the library catalog that describe reserved volumes begin with #R characters and show the media type, the VSN, the reserve information, and the reservation date and time. The information also includes the archive set component, path name component, and file system component, separated by two slashes (//).

Note - The slash characters do not indicate a path name. They serve to separate the components of a reserved name.

Example 12-16 Library Catalog Showing Reserved Volumes

The lines have been truncated to fit on the page.

6 00071 00071 lt 0xe8fe 12 9971464 1352412 0x6a000000 131072 0x
# -il-o-b----- 05/24/00 13:50:02 12/31/69 18:00:00 07/13/01 14:03:00
#R lt 00071 arset0.3// 2001/03/19 18:27:31
10 ST0001 NO_BAR_CODE lt 0x2741 9 9968052 8537448 0x68000000 1310
# -il-o------- 05/07/00 15:30:29 12/31/69 18:00:00 04/13/01 13:46:54
#R lt ST0001 hgm1.1// 2001/03/20 17:53:06
16 SLOT22 NO_BAR_CODE lt 0x76ba 6 9972252 9972252 0x68000000 1310
# -il-o------- 06/06/00 16:03:05 12/31/69 18:00:00 07/12/01 11:02:05
#R lt SLOT22 arset0.2// 2001/03/02 12:11:25

One or more of the reserve information fields can be empty, depending on the options defined in the archiver.cmd file. A reservation line is appended to the file for each volume that is reserved for an archive set during archiving.

You can also use the reserve and unreserve commands to reserve and unreserve volumes. For more information about these commands, see reserve(1M) in Sun QFS and Sun Storage Archive Manager Reference Manual and unreserve(1M) in Sun QFS and Sun Storage Archive Manager Reference Manual.

A volume is unreserved when it is relabeled because the archive data has been effectively erased.

You can display the reserve information by using the samu utility's v display or by using the archiver or dump_cat command in one of the formats shown in the following example:

# archiver -lv
# dump_cat -V _catalog-name_

Setting Archive Priorities: `-priority` Parameter

Archive-enabled file systems provide priorities for archiving files. Each file is assigned a priority computed from properties of the file and priority multipliers that can be set for each archive set in the archiver.cmd file. Properties include online/offline, age, number of copies made, and size.

By default, the files in an archive request are not sorted, and all property multipliers are zero. The result is that files are archived in first-found, first-archived order. To change the order in which files are archived, set priorities and sort methods. Examples of new priorities include:

Select the priority sort method to archive files within an archive request in priority order.
Change the archive_loaded priority to reduce media loads.
Change the offline priority to cause online files to be archived before offline files.
Change the copy# priorities to make archive copies in copy order.

Table 12-4 Archive Priorities

Archive Priority	Definition
`-priority age` value	Archive age property multiplier
`-priority archive_immediate` value	Archive immediate property multiplier
`-priority archive_overflow` value	Multiple archive volumes property multiplier
`-priority archive_loaded` value	Archive volume loaded property multiplier
`-priority copies` value	Copies-made property multiplier
`-priority copy1` value	Copy 1 property multiplier
`-priority copy2` value	Copy 2 property multiplier
`-priority copy3` value	Copy 3 property multiplier
`-priority copy4` value	Copy 4 property multiplier
`-priority offline` value	File offline property multiplier
`-priority queuewait` value	Queue wait property multiplier
`-priority rearchive` value	Rearchive property multiplier
`-priority reqrelease` value	Reqrelease property multiplier
`-priority size` value	File-size property multiplier
`-priority stage_loaded` value	Stage volume loaded property multiplier
`-priority stage_overflow` value	Multiple stage volumes property multiplier

For value, specify a floating-point number in the following range:

-3.400000000E+38 <= _value_ <= 3.402823466E+38

For more information about priorities, see archiver(1M) in Sun QFS and Sun Storage Archive Manager Reference Manual and archiver.cmd(4) in Sun QFS and Sun Storage Archive Manager Reference Manual.

Scheduling Archiving: -`startage`, `-startcount`, and `-startsize` Parameters

As the archiver scans a file system, it identifies files to be archived. Files that are recognized as candidates for archiving are placed in a list known as an archive request. At the end of the file system scan, the system schedules the archive request for archiving. The -startage, -startcount, and -startsize archive set parameters control the archiving workload and ensure the timely archival of files.

Table 12-5 -startage, -startcount, and -startsize Directives

Directive	Definition
`-startage` time	The amount of time that can elapse between the first file in a scan being marked for inclusion in an archive request and the start of archiving. Specify a time in the format described in Setting the Archive Age. If this variable is not set, the `interval` directive is used.
`-startcount` count	The number of files to be included in an archive request. When the number of files in the archive request reaches the this value, archiving begins. By default, count is not set.
`-startsize` size	The minimum total size, in bytes, of all files to be archived in an archive request. Archiving work is accumulated, and archiving begins when the total size of the files reaches the this value. By default, size is not set.

The examine=method directive and the interval=time directives interact with the -startage, -startcount, and -startsize directives. The -startage, -startcount, and -startsize directives optimally balance archive timeliness and archive work done. These values override the examine=method specification, if any.

The -startage, -startcount, and -startsize directives can be specified for each archive copy. If more than one of these directives is specified, the first condition encountered starts the archive operation. If none of these directives is specified, the archive request is scheduled based on the examine=method directive:

If examine=noscan, the default values of the directives are used: startage 10 minutes, startcount 10,000, and startsize 10 gigabytes. The archive request is scheduled according to the value of the interval= directive after the first file is entered in the archive request. This method is continuous archiving and is the default method.
If examine=scan|scaninodes|scandirs, the archive request is scheduled for archiving after the file system scan.

The archiver.cmd(4) man page provides examples that show how to use these directives.

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