On Tue, May 20, 2014 at 05:33:15PM +0200, Marko Weber|8000 wrote: > > hello, again me ;-) > > i use at runtime this command to backup root partition of a server: > > xfsdump -f /var/backup/root2.dump -l 0 -p 5 -L rootdump -M rootdump / > > > i googled around alot, cause a question wont get out of my mind: > is this backup consistent? > And what about consistency when i backup a mysql partition at runtime? First, define consistent.... If you define consistent as a point in time snapshot where everything is from the same point in time, then xfsdump does not provide you with that. You need to quiese mysql and snapshot the filesystem, then backup the snapshot to get a consistent point in time backup of the filesytem from the application data all the way down to the filesystem metadata. That's no different to any other backup process - even if you are using btrfs you still need to quiesce the application to get a consistent snapshot of the application data in the filesystem snapshot that you are backing up.... > but my most wondering is abot this: > > bunka ~ # df -h > Filesystem Size Used Avail Use% Mounted on > /dev/root 135G 11G 125G 8% / > > > but the saved dump shows: > > > bunka ~ # ls -lh /var/backup/ > > -rw-r--r-- 1 root root 8.4G May 20 17:29 root2.dump xfsdump stores information in a more compact form than the filesystem does on disk. It doesn't need all the metadata the filesystem has on disk to reference all the data you are backing up... Also, they may be some files maked as "no dump" that will be skipped, and other files that (e.g. iopen, unlinked tmpfiles) can't be found via a directory traversal and so aren't backed up. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
