On 12/3/2010 4:14 PM, Adam Tauno Williams wrote:
On Fri, 2010-12-03 at 12:51 -0800, John R Pierce wrote:
On 12/03/10 12:25 PM, Les Mikesell wrote:
Whenever anyone mentions backups, I like to plug the backuppc program (http://backuppc.sourceforge.net/index.html and packaged in EPEL). It uses compression and hardlinks all duplicate files to keep much more history than you'd expect on line with a nice web interface - and does pretty much everything automatically.
I'm curious how you backup backuppc, like for disaster recovery,
I know nothing about backuppc; I don't use it. But we use rsync with the same concept for a deduplicated archive.
archival, etc? since all the files are in a giant mess of symlinks
No, they are not symbolic links - they are *hard links*. That they are hard-links is the actual magic. Symbolic links would provide the automatic deallocation of expires files.
(for deduplication) with versioning, I'd have to assume the archive volume gets really messy after awhile, and further, something like that is pretty darn hard to make a replica of it.
I don't see why; only the archive is deduplicated in this manner, and it certainly isn't "messy". One simply makes a backup [for us that means to tape - a disk is not a backup] of the most current snapshot.
Actually, making a backup of BackupPC's data pool (or just moving it to new disks) does get messy. With a large pool there are so many hardlinks that rsync has trouble dealing with it, eats all your memory, and takes forever. This is a frequent topic of conversation on the BackupPC list. However, the next major version of BackupPC is supposed to use a different method of deduplication that will not use hardlinks and will be much easier to back up.