(Illustration by Gaich Muramatsu)
On Wed, Aug 06, 2014 at 03:21:17PM +0200, u-codalist-z149_at_aetey.se wrote: > Backup is one of the subsystems in Coda which I do not see as satisfactory. > That's why we backup on file level despite the shortcomings of such > a fashion. For people who are not aware, the problems with file level backup are: - Coda's inodes have no guarantee of being unique as the internal identifier is a 128-bit file identifier. So any backup program that tries to identify hardlinks based on only the 32-bit inode number value may skip files believing they were already backed up. - When there is a conflict, all files underneath the conflict are invisible to the backup program. - (this one may be a benefit) when parts of the tree are inconstent between servers backup is slowed down because it triggers server-server resolution for all inconsistent objects. - Backup tools don't know how to backup/restore ACLs. We actually use Coda's built in volume dump backup mechanism which has the ability to create consistent atomic snapshots across all replicas of a volume which are then efficiently streamed from the server using volutil dump. Our last three backup setups (Amanda based, BackupPC based and custom) all used volutil dump | codadump2tar, which returns a standard tar archive of all files in a volume replica, but we do also lose ACL information. I've thought about adding a shell script in the archive that an admin can run to set the ACLs after a restore. JanReceived on 2014-08-06 09:50:21