Selective backup?

[ldmwndletsm]

Running 8.1.3 on Linux.

If you ever need to start over with a new "first-time" full (and then incr thereafter) of a given file space, but you don't want to lose what TSM already has in its database, will the selective backup do that? And then you just continue with incrementals as before? But you could still restore older data from before you ran the selective?

... maybe you discover something wrong with the configuration, or maybe you just want to get a complete new copy, all on more recent or newer media or contiguous tapes since it may have been spread out on a lot of tapes over time (pieces/parts all over), even assuming collocation.

Or would you instead have to delete the file space for the node from the server's database and run another incr? Seems illogical, but I'm not sure here.

 

[marclant]

Yes and no. A selective will backup everything that is not excluded even if they didn`t change since the last backup. But, if all the previous incrementals were successful, you won't get a better backup if you run a selective. And you may lose some of the older backups because the selective counts as a version because it backs up files that have not changed.

I'm not sure which problem you are trying to solve, hard to say if it will do what you want it to or not.

 

[ldmwndletsm]

Thanks much. This answers the question.

The purpose (theoretically. I don't actually have to do this) would in fact be to re-back up everything. The versions limit would not be a factor here since it's 'No Limit'. One problem we might want to solve would be if corruption were found and then corrected for a lot of the data, and/or if it had been a long time, and we simply wanted another complete backup of all the data, fresh from disk. We could, of course, make another copy from the primary pool tapes, but this might be slow, depending on how many tapes those backups were spread out across, and reading from tape, of course, is usually slower than from the disk (using a disk pool volume and then to tape). There is also the possibility of bit rot. Clearly, one should be periodically testing tapes (both off-site and on-site), but we might feel more comfortable making another fresh backup once very so many moons of some very specific data, not most.

But if we switch to newer generation media, and we don't want to have to read all the older tapes then how else could we accomplish having everything on newer media?

 

[marclant]

But if we switch to newer generation media, and we don't want to have to read all the older tapes then how else could we accomplish having everything on newer media?

A selective would accomplish that. Or you could rename the filespaces, that will cause the next backup to backup everything since the filespace won't exist, a new one will be created and every file will be candidate for backup.

 

[ldmwndletsm]

Got it.