topic Re: Incremental/Full restore in Operating System - HP-UX

Incremental/Full restore

Roger Baptiste — Wed, 03 Apr 2002 16:43:38 GMT

hi,

When Restoring from a incremental backup, omniback restores all the files from the last full backup and then overwrites them from the incrementals. This means that it is restoring the "delta" files (i.e the files which changed between backups and are in the incrementals) more than once. This is a waste of restore time/bandwith.

Since omni has all the information it needs before the restore, shouldn't it be picking only the latest version of the files, rather than restoring from full , than overwriting it from incremental backups?

Is there any way to circumvent this?
Is this the way it works in Omni4 too?

thanks
raj

Re: Incremental/Full restore

A. Clay Stephenson — Wed, 03 Apr 2002 16:51:38 GMT

No, OB2 only concerns itself with the timestamp of the file itself. To do it your way, it would have to do something like a CRC check of each block and then store that data in its database - a tremendous amount of overhead that would slow down backups. Remember, the idea is to make backups (which are done often) as fast as possible; the speed of restores which are typically seldom done is of far less importance.

OB2 4.x is the same.

Re: Incremental/Full restore

Helen French — Wed, 03 Apr 2002 18:15:11 GMT

Hi Raj,

I think you are doing a full restore here. In that case the only option left is restore FULL, then restore the latest incrementals. I think if you do a single file/files restore it wont check the FULLs, but will take from the incrementals.

HTH,
Shiju

Re: Incremental/Full restore

Deshpande Prashant — Wed, 03 Apr 2002 19:03:48 GMT

Hi Raj..
Do a parallel restore of multiple files with what ever version (latest?) you want. Or try manually with omnir command
#omnir -filesystem / -session

Thanks.
Prashant.