HP StorageWorks Reference Information Storage System V1.4 Administrator Guide (T3559-96027, March 2006)

The secondary smart cell usually performs this backup. However, the primary cell in the group performs
the backup if the secondary cell is unavailable.
Thesmartcellitselfinitiatesthebackup.BecausethisisautomaticanddoesnotinvolveTivoli’sinternal
scheduler, the TSM c on figuration does not include a schedule for smart cell backups.
Separate Group Volumes
An option for Separate Group Volumes is available in the Backup section of the RISS Master Configuration
File. If selected, this o ption ensures tha t data backed up from one smart cell group is never stored
onthesameme
dia as another sm art cell group.
Only select t
his option if you specifically require this functionality, because it complicates the creation
of offlinecopiesandleadstoalessefficient use of backup tapes.
If you select the Separate Group Volumes option, a separate TSM node object and accompanying
objects for each smart cell group are created. After you have selected this option, it cannot be changed
without first removing all existing smar t cell backups.
TSM backup terms
The following section contains shor t descriptions of important TSM terms and concepts and how they
relate to each other.
The three basic TSM elements a re library, device,andpath:
A library is a set of one or more drives that have similar media mounting requirements. A library can
also include robotic devices.
A device represents a tape or optical drive.
A path describes a one-to-one relationship between a source and a destination. Data can flow from
source to destination and back. The path is the element that connects the server, library, and device.
A device class is a log ical collection of devices for similar media. Every device that is attached to a library
hastobeamemberofadeviceclass.Thedeviceclasscontainsthelibrarynameandthedevicetype.
A storage volume is the basic unit of storage m ed ia (for example, a tape). Storage volumes are grouped
into storage pools, which can be arranged in a storage hierarchy. The term server storage represents all
storage pools in the system.
The following terms define how client data is hand led:
• A policy domain is a log ical construct that keeps policy sets, management classes, and copy
groups together.
• A policy set is a set of rules that defines how to handle client data within TSM. (A policy is a rule.)
• A management class determines how client files are managed and where they are initially stored.
It also contains information about how to handle files that clients back up, archive, or migrate.
• Each management class can contain up to two copy groups:abackupcopygroupandan
archive copy group. Each of them points to a destination, which is a storage pool where files
are first stored after they are backed up or a rchived. A copy group is used to define how many
versions of a filearekeptandhowlongclientdataisretained.
The figure below shows how these categories are related.
158
Backup system administration