Defining a storage pool — logical

Tivoli Storage Manager has two types of storage pools:

• Primary storage pools

• Copy storage pools

A primary storage pool can use random access storage (DISK device class) or sequential access storage (for example, tape, optical or file device classes). A copy storage pool can use only sequential access storage.

5.7.4.1 Primary storage pool for a manual library

Following the device class, you can now define the storage pool you are going to use with the library.

The following command defines a storage pool named TAPEDATA using the device class named C8MM. The high migration parameter is set to 100 to stop migration because there is no NEXTSTGPOOL for this storage pool to migrate to.

The MAXSCRATCH value of 10 means that when 10 scratch tapes have been used, the storage pool indicates that it is full — this may not be desirable.

However, this parameter is used to estimate the total number of volumes in the pool and the corresponding estimated capacity of the pool. MAXSCRATCH is a required value for sequential type storage pools. It can be increased at any time if more volumes are needed in the storage pool, however it is not a good practice to set MAXSCRATCH higher than the actual number of volumes available.

5.7.4.2 Primary storage pool for disk

Using the Tivoli Storage Manager predefined device class of DISK, you can define a primary disk storage pool.

The following command defines a storage pool named DISKDATA with a high migration threshold of 70% and a low migration threshold of 30%. It uses the predefined Tivoli Storage Manager device class of DISK^.

tsm: TSM010> define stgpool tapedata c8mm highmig=100 maxscratch=10 ANR2200I Storage pool TAPEDATA defined (device class C8MM).

tsm: TSM010> query stgpool tapedata

Storage Device Estimated Pct Pct High Low Next Pool Name Class Name Capacity Util Migr Mig Mig Storage

(MB) Pct Pct Pool

--- --- --- --- --- ---- ---

---TAPEDATA C8MM 0.0 0.0 0.0 100 70

5.7.4.3 Primary storage pool for sequential disk

This is where a disk can simulate a sequential device, such as tape.

The following command defines a storage pool named DISKFILE using a device class named CFILE. Because it simulates a sequential storage pool, the

MAXSCRATCH parameter must be included, and because there is no next storage pool in this case, migration is disabled.

Operation compared to a ’real’ sequential access storage pool

When using a sequential access storage pool with a FILE device class, it looks and operates slightly differently compared to a storage pool mapped to a physical tape or optical device. When disk is used, the server opens a file when one is required, and so the storage pool shows 0.0 Estimated Capacityuntil data has been sent to it. Following a client backup operation to this storage pool, we can see the capacity increase. Checking the volume used for this operation, the server has created a file named00000005with an extension of.BFSto store a client’s data. Because of this difference in operation, volumes do not have to be defined for this type of diskpool — the server creates files itself, within the overall maximum capacity of the device class. You would only manually define volumes, rather than allowing them to be automatically assigned, if for some reason you wanted to have control over the volume names. Note: There are suffixes other than .BFS that may be created when using a sequential pool for other types of operation, such as backing up the server database or a primary storage pool.

tsm: TSM010> define stgpool diskdata disk description="Data Storage" \ cont> high=70 low=30

ANR2200I Storage pool DISKDATA defined (device class DISK).

tsm: TSM010> query stgpool diskdata

Storage Device Estimated Pct Pct High Low Next Pool Name Class Name Capacity Util Migr Mig Mig Storage

(MB) Pct Pct Pool

--- --- --- --- --- ---- ---

---DISKDATA DISK 0.0 0.0 0.0 70 30

tsm: TSM010> define stgpool diskfile cfile maxscratch=100 highmig=100 ANR2200I Storage pool DISKFILE defined (device class CFILE).

tsm: TSM010> query stgpool diskfile

Storage Device Estimated Pct Pct High Low Next Pool Name Class Name Capacity Util Migr Mig Mig Storage

(MB) Pct Pct Pool

--- --- --- --- --- ---- ---

---DISKFILE CFILE 0.0 0.0 0.0 100 70

Single drive reclamation using disk for reclaim storage pool

Reclamation can be performed by a single drive in Tivoli Storage Manager by specifying the RECLAIMSTGPOOL parameter. This parameter points to another storage pool that can be used as the holding area for the data being

consolidated. The holding area then refers back to the original pool being reclaimed as its next pool to migrate to. Reclamation was discussed already in Section 5.4, “Reclamation - how to use fewer tapes” on page 84.

The following command updates the existing storage pool named TAPEDATA to use the disk storage pool named DISKFILE to hold data temporarily when performing reclamation.

tsm: TSM010> query stgpool diskfile

Storage Device Estimated Pct Pct High Low Next Pool Name Class Name Capacity Util Migr Mig Mig Storage

(MB) Pct Pct Pool

--- --- --- --- --- ---- ---

---DISKFILE CFILE 1,200.0 0.3 1.0 100 70

tsm: TSM010> query volume stgpool=diskfile

Volume Name Storage Device Estimated Pct Volume

Pool Name Class Name Capacity Util Status (MB)

--- --- --- --- --- ---/tsm/stgpool/00000005.B- DISKFILE CFILE 12.0 29.8 Filling

FS

tsm: TSM010> update stgpool tapedata reclaimstgpool=diskfile ANR2202I Storage pool TAPEDATA updated.

tsm: TSM010> query stgpool tapedata format=detail Storage Pool Name: TAPEDATA

Delay Period for Volume Reuse: 0 Day(s) Migration in Progress?: No

The disk storage pool with a device class of FILE, named DISKFILE, is then updated to point back to the pool being reclaimed.

tsm: TSM010> update stgpool diskfile nextstgpool=tapedata ANR2202I Storage pool DISKFILE updated.

tsm: TSM010> query stgpool diskfile

Storage Device Estimated Pct Pct High Low Next Pool Name Class Name Capacity Util Migr Mig Mig Storage

(MB) Pct Pct Pool

--- --- --- --- --- ---- --- ---DISKFILE CFILE 1,200.0 0.3 1.0 100 70 TAPEDATA

5.7.4.4 Copy storage pool

The copy storage pool is defined so that it can be used to backup the primary storage pools. This pool has a reuse delay of five days before reclaimed offsite tape volumes are moved back to the scratch pool. This is to allow for a long company shutdown, such as Easter holidays, where the offsite data must remain intact in case a disaster occurs onsite and it is required. You must set this value equal to the longest period of time before normal operations resume for you.

Normal operations (database and primary pools) are backed up and volumes are taken offsite.