Recently I switched the compression format for my backups from TGZ to ZIP, since Virtualmin needs a very long time to scan large TGZ backup files for contents ("Show what will be restored"), even before the actual restore process. Probably due to the fact that the TAR needs to be fully extracted from the GZ before it can be evaluated.
But, in ZIP format, no incremental backups are possible. Those are created as full backups, which I just noticed when a backup failed due to "no space left on device". The Samba mount where the backups get stored was indeed full, since the last 10 backups occupied 5 GB each (full) instead of 100 MB (incremental).
Anything we can do about this? I'd like an archive format that can be quickly scanned, but that still offers incremental backups.
Comments
Submitted by JamieCameron on Thu, 02/17/2011 - 13:47 Comment #1
That would be nice, but as far as I can tell the zip command (and format) has no support for incremental backups ..
Submitted by Locutus on Thu, 02/17/2011 - 14:00 Comment #2
Hmm.. What about another method of differential file selection? I've seen a script where they use the
findcommand to create a list of files that have a newer date than the full backup, and feed that as list of files to compress to ZIP.If that's not possible, there should at least be a clear warning that "incremental" does not work when ZIP is selected. Otherwise users might - like me - be surprised by out-of-space backup media.
Submitted by JamieCameron on Thu, 02/17/2011 - 17:28 Comment #3
I will hide the incremental option and prevent it from being used if ZIP format is enabled .. that should prevent this issue.
Submitted by Issues on Thu, 03/03/2011 - 18:22 Comment #4
Automatically closed -- issue fixed for 2 weeks with no activity.