ldmwndletsm
ADSM.ORG Senior Member
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I ran an `audit volume fix=no` on several tapes as a test. No discrepancies were reported, but I have several questions:
1. Does the audit actually read each file on the tape, just as a recover operation would, or does it instead read some type of metadata on the tape to compare with the database?
In other words, if you were restoring data to the backup server from the same tape, and the tape drive was local (no network) then aside from the time to write to disk would the speed to read the data from tape be the same as the audit's reading of the data? Is that part of the operation the same?
2. What happens if you audit volumeA after you move the data to volumeB?
I would assume that if no newer data was written to volumeA (read-only) then TSM is no longer tracking any data for tape A. So a `q content volumeA` would report nothing. Data is still physically on the tape, of course, but TSM no longer knows about it being there, only now volumeB. But I wonder about an audit? Would it:
A. Fail immediately?
B. It would try to read the tape (surely it could read it), but then it would report an error for each file since that file would not be listed in the DB for volumeA?
C. It would run silently and then end with the usual summary report wherein everything would then be reported as missing or some such thing?
I meant to try this after data was moved to another tape, but the volume was returned to the scratch pool (resuse delay for the stgpool expired) and recycled and then written to before I thought about it.
1. Does the audit actually read each file on the tape, just as a recover operation would, or does it instead read some type of metadata on the tape to compare with the database?
In other words, if you were restoring data to the backup server from the same tape, and the tape drive was local (no network) then aside from the time to write to disk would the speed to read the data from tape be the same as the audit's reading of the data? Is that part of the operation the same?
2. What happens if you audit volumeA after you move the data to volumeB?
I would assume that if no newer data was written to volumeA (read-only) then TSM is no longer tracking any data for tape A. So a `q content volumeA` would report nothing. Data is still physically on the tape, of course, but TSM no longer knows about it being there, only now volumeB. But I wonder about an audit? Would it:
A. Fail immediately?
B. It would try to read the tape (surely it could read it), but then it would report an error for each file since that file would not be listed in the DB for volumeA?
C. It would run silently and then end with the usual summary report wherein everything would then be reported as missing or some such thing?
I meant to try this after data was moved to another tape, but the volume was returned to the scratch pool (resuse delay for the stgpool expired) and recycled and then written to before I thought about it.