Increase EstCapacity of Tape Storage Pool

[TitusBandugula05011988]

Hello All,

I have two storage pools which share the same library (LTO7)
One pool is configured as STG_POOL_TAPE and the other is integrated with Netapp to use the same library STG_POOL_NETAPP.

I have a total of 58 scratch tapes available from 77 tapes.

The Est.Capacity of STG_POOL_TAPE is 500TB but for STG_POOL_NETAPP is only 8TB.

The maxscratch volume for both the pools are set to 300 and the maxcapacity of both the device classes is set to 100G.

I want both the pools to have Est.Capacity of 300TB

 

[marclant]

==========================
For tape and FILE devices, the estimated capacity for the
storage pool includes the following factors:
* The capacity of all the scratch volumes that the storage
pool already acquired or can acquire. The number of scratch
volumes is defined by the MAXSCRATCH parameter on the DEFINE
STGPOOL or UPDATE STGPOOL command.
* The capacity of all the private volumes that are defined to
the storage pool when you use the DEFINE VOLUME command.
* The estimated capacity of the storage pool cannot be more
than the capacity of the total file systems that are used by
the device class.

source: HELP QUERY STGPOOL
==========================
So it's all the private tapes + scratch tapes combined. So if you have one pool with more private tapes than the other, that explains it.

 

[TitusBandugula05011988]

Only two volumes have been allocated to the STG_POOL_NETAPP. Rest are DBBackup and Data + 58 scratch volumes.

 

[marclant]

Well, either way. It's impossible to change the estimated capacity. It's exactly that, an estimate. For tape pools, that number is not of much value anyway, especially when you have multiple pools picking from the same scratch tapes. Making sure there are scratch tapes available is the primary concern.

 

[TitusBandugula05011988]

So the TSM won't fail the backup more than the Est.Capacity of the pool (tape)?

 

[DazRaz]

The maxcapacity of your LTO7 device class setting is really low. I would have thought that a setting of between 6-15TB would be better. This way TSM will expect it can save at least the uncompressed capacity of files on the LTO7 tapes and the estimated capacity will change to suit.

As said, the estimated capacity doesn't affect much but if you are going to send large backups there, TSM will need to think the capacity is available.