Storage management policies are rules your administrator defines in order to manage your backups and archives on the server. You can associate (or bind) your data to these policies; then when the data is backed up or archived, it is managed according to policy criteria. Policy criteria include a policy domain, a policy set, a copy group, and a management class.
Policies determine:
This chapter explains:
A policy domain is a group of clients with similar requirements for backing up and archiving data. Policy domains contain one or more policy sets. An administrator uses policy domains to manage a group of client nodes in a logical way. For example, a policy domain might include:
TSM includes a default policy domain named Standard. At first, your client node might be associated with the default policy domain. However, your administrator can define additional policy domains if there are groups of users with unique backup and archive requirements.
A policy set is a group of one or more management classes. Each policy domain can hold many policy sets. The administrator uses a policy set to implement different management classes based on business and user needs. Only one of these policy sets can be active at a time. This is called the active policy set. Each policy set contains a default management class and any number of additional management classes.
A management class is a collection of backup and archive copy groups that establishes and contains specific storage management requirements for backing up and archiving data. An administrator can establish separate management classes to meet the backup and archive requirements for different kinds of data, such as:
Note: | If you have the Tivoli Space Manager client installed, it can also contain specific requirements for migrating files to storage. |
Most of the work you do with storage management policies is with management classes. You must associate (or bind) each file and directory that you back up and each file that you archive with a management class. If you do not associate a file with a management class, TSM uses the default management class in the active policy set. If you do not specify a management class for directories, TSM uses the management class in the active policy set specifying the longest retention period.
Use an include-exclude list to associate files with management classes. See Selecting a Management Class for Files for more information. To associate directories with a management class, use the dirmc option. See Selecting a Management Class for Directories for more information.
Within a management class, the specific backup and archive requirements are in copy groups. Copy groups define the specific storage management attributes that describe how the server manages backed up or archived data. Copy groups include both backup copy groups and archive copy groups. A management class can have one backup copy group, one archive copy group, both, or neither.
A backup copy group contains attributes that are used during the backup process to determine:
It also contains attributes to manage the backup versions of your files on the server. These attributes control:
An archive copy group contains attributes that control:
A specified number of days are permitted to retain a backup version, known as grace period backup retention, or an archive copy, known as grace period archive retention, when the server is unable to rebind the file to an appropriate management class. For more information about grace periods, see Using a Retention Grace Period.
Before you select the management classes you want to use, click Display policy information from the Utilities menu to determine which ones are available. You can also use the detail option on the query mgmtclass command to view the available management classes.
The Display policy information window provides the following information:
If you have the HSM client installed, the management class information can also include the following information:
Figure 7 shows the default values for the backup and archive copy groups in the
standard management class. Each attribute is discussed in more detail
immediately following the table.
Figure 7. Default Values in the Standard Management Class
Attribute | Backup Default | Archive Default |
---|---|---|
Copy group name | Standard | Standard |
Copy type | Backup | Archive |
Copy frequency | 0 days | CMD (Command) |
Versions data exists | Two versions | Does not apply |
Versions data deleted | One version | Does not apply |
Retain extra versions | 30 days | Does not apply |
Retain only version | 60 days | Does not apply |
Copy serialization | Shared static | Shared static |
Copy mode | Modified | Absolute |
Copy destination | Backuppool | Archivepool |
Retain versions | Does not apply | 365 days |
Figure 8 shows the default values for space management attributes in
the standard management class if you have the HSM client installed.
Figure 8. Default Values for Space Management Attributes
Attribute | Default |
---|---|
Space Management Technique | None |
Auto Migrate on Non-Usage | 0 |
Backup Required Before Migration | Yes |
Destination for Migrated Files | Spacemgpool |
The name of the copy group. The default value for both backup and archive is Standard.
The type of copy group. The value for backup is always Backup, and the value for archive is always Archive.
Copy frequency is the minimum number of days that must elapse between successive incremental backups. Copy frequency works with the mode parameter. For example, if frequency is zero (0) and mode is modified, a file or directory is backed up only if it changed since the last incremental backup. If frequency is zero (0) and mode is absolute, a file is backed up every time you run an incremental backup against it. This attribute is not checked for selective backups.
For archive copy groups, copy frequency is always CMD (command). There is no restriction on how often you archive a file.
The Versions Data Exists attribute specifies the maximum number of different backup versions retained for files and directories currently on your drive. If you select a management class that permits more than one backup version, the most recent version is called the active version. All other versions are called inactive versions. If the maximum number of versions permitted is five, and you run a backup that creates a sixth version, the oldest version is deleted from server storage.
The Versions Data Deleted attribute specifies the maximum number of different backup versions retained for files and directories that you erased from your drive. This parameter is ignored as long as the file or directory remains on your drive.
If you erase the file or directory, the next time you run an incremental backup, the active backup version is changed to inactive and the oldest versions are erased that exceed the number specified by this parameter.
The expiration date for the remaining versions is based on the retain extra versions and retain only version parameters.
The Retain Extra Versions attribute specifies how many days all but the most recent backup version is retained. The most recent version is the active version, and active versions are never erased. If Nolimit is specified, extra backup versions are deleted based on the versions data exists or the versions data deleted parameter settings.
The Retain Only Version attribute specifies the number of days the last remaining inactive version of a file or directory is retained. If Nolimit is specified, the last version is retained indefinitely.
The Copy Serialization attribute determines whether a file can be in use during a backup or archive, and what to do if it is. The value for this attribute can be one of the following:
The Copy Mode attribute determines whether a file or directory is considered for incremental backup regardless of whether it changed or not since the last backup. TSM does not check the mode for selective backups. The value for this parameter can be one of the following:
Names the destination where backups or archives are stored. The destination can be either a storage pool of disk devices or a storage pool of devices that support removable media, such as tape.
Specifies the number of days an archived file remains in storage. When the specified number of days elapse for an archived copy of a file, deletes it from storage.
If the default management class meets the backup and archive requirements for all the files on your workstation, it is not necessary to take any action to associate your files with that management class. This is done automatically when you back up or archive your files.
When selecting a different management class for your files, consider these questions:
If you attempt to back up a file associated with a management class that does not contain a backup copy group, the file is not backed up.
If you attempt to archive a file associated with a management class that does not contain an archive copy group, the file is not archived.
Mode and frequency work together to control how often a file is backed up when you use incremental backup. TSM does not check those attributes for selective backup.
If serialization is shared dynamic or dynamic, you might get fuzzy backups or archive copies. Verify that this is acceptable. For example, you might want to use shared dynamic or dynamic serialization for a file to which log records are continuously added. If you used static or shared static serialization, the file might never back up because it is constantly in use. With shared dynamic or dynamic serialization, the file is backed up, but the backup version of the file might contain a truncated message. Do not use shared dynamic or dynamic serialization for a file if it is very important that the backup version or archive copy contain all changes.
Note: | If you have the HSM client installed, and you want a file to be eligible for migration, assign the file to a management class that also contains the appropriate space management attributes. |
A management class defines when your files are included in a backup, how long they are kept on the server, and how many versions of the file the server should keep. The server administrator selects a default management class. You can specify your own management class to override the default management class.
If you have the HSM client installed, the management class assigned to a file also defines whether a file can be migrated to storage automatically, whether a file is eligible for automatic migration, and whether a current backup version of a file must exist before the file can be migrated.
You can assign a management class for a file or file group by using an include statement to create an include-exclude list in your client systems options (dsm.sys) file or the include-exclude file specified by the inclexcl option.Management class names are not case-sensitive. For example, to associate all the files in the costs directory with a management class named budget, you would enter:
include /home/jones/costs/* budget
To specify a management class named managall to use for all files to which you do not explicitly assign a management class, you would enter:
include * managall
The example below demonstrates how to use a management class:
exclude /.../*.sno include /home/winter/.../*.ice mcweekly include /home/winter/december/*.ice mcdaily include /home/winter/january/*.ice mcmonthly include /home/winter/winter/white.sno
Processing follows these steps:
To specify your own default management class for files that are not explicitly included, specify:
include * mgmt_class_name
as the first include or exclude option defined.
When you archive a file using the graphical user interface, you can select a different management class to override the management class assigned to the file.
When you archive a file, you can override the assigned management class using the graphical user interface (GUI), or using the archmc option on the archive command. To use the GUI, press the Archive Options button on the archive tree to override the management class and select a different management class. For example, to associate the file, /home/jones/budget.jan, with the management class ret2yrs, you would enter:
dsmc archive -archmc=ret2yrs /home/jones/budget.jan
If the management class in your active policy set containing the longest retention period meets your backup requirements for directories, it is not necessary to take any action to associate directories with that management class. TSM does it automatically when it backs up your directories.
If the default management class does not meet your requirements, select a management class with an adequate retention period specified on the retain only version parameter. You should keep directories at least as long as you keep the files associated with those directories.
To assign a management class other than the default to directories, use the dirmc option in your client system options file. For example, to assign a management class named direct1 to your directories, you would enter:
dirmc direct1
Note: | An archive management class is assigned to directories whose retention period meets or exceeds that of the files contained in those directories. The management class is rebound as needed to ensure that directories with files do not expire. |
Binding associates a file with a management class. When you back up a file for the first time, TSM binds it to either the default management class or the management class specified in your include-exclude list. In later backups of the same file, if you change the management class, both active and inactive versions are bound again to the new management class.
If the backup copy group for the management class specifies keeping multiple backup versions of the file, and you request multiple backups, the server always has one active backup version (the current version) and one or more inactive backup versions of the file. All backup versions of a file are bound to the same management class and are managed based on the attributes in the backup copy group.
When you archive a file for the first time, TSM binds it to the default management class, to the management class specified in your include-exclude list, or to a management class you specify when modifying your archive options during an archive.
Archived files are never rebound to a different management class. If you change the management class for a file, any previous copies of the file that you archived remain bound to the management class specified when you archived them.
Backups of files are bound again to a different management class in the following conditions. In each condition, the files (active and inactive) are not bound again until the next backup.
TSM also provides a backup retention grace period and an archive retention grace period to help protect your backup and archive data when it is unable to rebind a file to an appropriate management class. The backup retention grace period is used when:
The backup retention grace period, defined in your policy domain, starts when you run an incremental backup. The default is 30 days. However, your administrator can lengthen or shorten this period.
When TSM manages a file using the backup retention grace period, it does not create any new backup versions of the file. All existing backup versions of the file expire 30 days (or the number of days specified in your policy domain) from the day they are marked inactive.
For archived files, if the management class to which a file is bound no longer exists, and the default management class does not contain an archive copy group, the archive retention grace period defined in your policy domain is used. The default retention period is 60 days. However, your administrator can lengthen or shorten this period.