π
2014-05-20 01:01
in Btrfs, Linux
How to manage historical snapshots of backups with Btrfs
I have a setup where I backup a certain number of machines to a central server. There are multiple ways to do hierarchical backups with btrfs.
snapshots and rsync on top
http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img33.html
not great because of COW relationship lost to unix tools,
not great because backing up server on another one requires a lot more snapshots of snapshots for btrfs send of old things that never change
works for deduping data that partially changes or changes owners
cp -a --link + rsync
http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img34.html
newer btrfs should be ok with many hardlinks
du can figure out the data saved
you can use hardlinks.py instead of bedup
can be transferred via cp/rsync without losing links
but hardlinks will not work across subvolumes
cp -a --reflink + rsync
http://marc.merlins.org/linux/talks/Btrfs-LC2014-JP/html/img35.html
very nice, does not require hardlinks which you can't do across subvolumes
works for deduping data that partially changes or changes owners
but totally lost as soon as you copy it anywhere else (unless you use btrfs send) |