How to free some tapes containing files migrated using HSM?

[tivolimistery]

Hi All,

I would ask you some technical information about the correct procedure to free a lot LTO4 tapes containing migrated file.
I'll try to explain my problem.

Our IBM TS3584 tape library is almost full. No empty slots are available and all tapes are full.
Using Tivoli Storage Manager for Space Management have been migrated about 1PB of data (from a GPFS file system to tapes).
The content of the storage pool dedicated to HSM managed data has been "duplicated" using the TSM copy storage pool feature.

We need to delete a great number of migrated file to free some LTO4 tapes.
But before proceeding I would ask you some information:

- what happen when I delete stub files on HSM managed file system?
- when they will be really removed from related tapes on primary storage pool?
- they will be automatically removed from copy storage pool also?

Someone can help me to understand what I have to do (after deleting stub files on file system) in order to manually control and speed up the process needed to free some tapes?

Thanks in advance,
Mauro T.

 

[marclant]

Hi All,
- what happen when I delete stub files on HSM managed file system?

Once HSM updates the TSM Server that the file is deleted, it's removed from the TSM Server's inventory, still physically on tape, but space is flagged as reclaimable.

- when they will be really removed from related tapes on primary storage pool?

When you run reclamation on the primary storage pool

- they will be automatically removed from copy storage pool also?

When you run offsite reclamation on the copy pool.

 

[marclant]

If you are not doing reclamation already, it's possible that you already have tapes eligible for reclamation. You can check with this query:

select stgpool_name,volume_name,pct_reclaim from volumes where pct_reclaim>50

I used 50% because that's a common reclamation threshold.

 

[tivolimistery]

Hi Marclant,

thank you very much for your answer.
Just another question: some tapes of copy pool are not offsite (they are still in our tape library)... do you think that deleted files contained in insite tapes will be flagged as deleted automatically? In other words, if I delete a file from primary pool, is it marked as deleted on copy storage pool automatically?

Thank you very much...
I'm sorry if my questions are so trivial

 

[marclant]

When an object is expired/deleted from the TSM inventory, it includes all copies, primary and copy, regardless of physical location because it's only removed from the database at this point. Space only becomes available on tape once reclamation is done.

 

[tivolimistery]

Thank you again, Marclant !

A last question, I Promise : If I will decide to remove some copystorage pool tapes, what will happen to related tapes on primary storage pool? they will be deleted too?!

Regards,
Mauro

 

[marclant]

Nothing happens to the primary storage pool when you do something to the copy storage pool

 

[tivolimistery]

Thank you. Have a nice day !!!