On Tue, Feb 26, 2013 at 5:26 PM, John R Pierce pierce@hogranch.com wrote:
don't have anywhere near that sort of uptime requirements, but when data starts spiralling out into the multi-terabytes with billions of file links, rsync is painfully slow.
Yes, the one problem with backuppc is that the number of hardlinks it uses to de-dup the data makes it a big problem to copy its archive as anything but an image-type copy.
the use case is more like, if the primary backup server fails, I'd like to have the secondary backup server running within a few hours of futzing with the existing backups available for recovery.
maybe I should use backupPC's archiving feature, but if I have to restore 20TB or whatever of files and links from an archive, that could well take the better part of a week.
The simple approach is to run another independent instance of backuppc, but you may run into problems with the timing if you have a small backup window.
the way I figure it, drbd would give me a backup copy of the backup system thats ready for near immediate use. failover would be a manual process, but simple and quick (stop drbd, mount the archive, start the standby backup PC server)..
That should work, but what happens if they ever get out of sync? How long will it take drbd to catch up with something that size?