Tom Holroyd wrote:
On Wed, 2008-03-19 at 17:24 -0400, Tom Holroyd wrote:
Show of hands: compress backups? Or 1:1 copy.
Summary. More than 2:1 favor 1:1. If you do compress, compressing the entire backup is bogus, it should be done file by file, and preferably by the backup device.
The interesting news is backup verification. I typically look at the file sizes and go, "yeah, it ran." Prob'ly not good enough.
Backuppc keeps only one linked copy for all instances of the same file that appear - but full runs will replace any changed content. Even if use rsync and tell it to cache it's block checksums to improve speed, it will still compare a certain percentage of the stored file contents on each run.
Also, one can argue in favor of FEC for archival storage, so if you lose a track or set of blocks you can still recover. I backup to RAID.
I mirror the whole backuppc filesystem to disks that are rotated offsite. I'd like to have something like the zfs incremental block-level send/receive instead, though.