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Heh apologies, my fault for trying to be clever, the mechanism I actually use is incremental and deduplicated. I substituted it for tar to simplify. I actually

Heh apologies, my fault for trying to be clever, the mechanism I actually use is incremental and deduplicated. I substituted it for tar to simplify. I actually use ZFS (filesystem), so my backup flow is closer to: TSTAMP="backup-$(date "+%Y%m%d-%H%M%S")" zfs snapshot -r $TSTAMP zfs send $TSTAMP | \ xz -z | \ openssl enc -aes-256-cbc -e -salt | \ > /mnt/your/networked/google/drive/backup.$(hostname -a).$TSTAMP.aes.tar.xz The underyling ZFS filesystem is deduplicated at filesystem level, and snapshots are incremental. THere're a few other minor differences (the dest is another ZFS host which syncs to Google drive, and I nuke the local snapshot after send because RAID 1+0 space is more expensive than RAID1 .. )

foobarqux 13y ago
I would like to do something similar with BTRFS. How are your snapshots incremental? In BTRFS you would need to specify a base snapshot. What is the restore process? You init a zfs file systems and then zfs receive the backups in chronological order? How are the dependencies between snapshots managed?
- vbit 13y ago
  The 'zfs send' command will send an incremental snapshot if you specify '-i snap1 snap2'. To restore, of course, you'll have to have snap1, and then you can apply the increment.
  - foobarqux 13y ago
    That's what I thought. I wanted to know if the OP had some way to manage the dependencies between snapshots.
Nanzikambe 13y ago
To answer my own question: deduplication :) I had not considered multiple backup sources, mine is deduplicated per host, am I to understand tarsnap is deduplicated across all hosts sharing a set of keys?
- beagle3 13y ago
  I think that's the case. Note: https://github.com/bup/bup https://github.com/bup/bup does that too (though it does not encrypt), and http://liw.fi/obnam/ http://liw.fi/obnam/ does too (and it does encrypt). What tarsnap gives you that obnam doesn't is (a) managed cloud storage, (b) tarsnap's history and reputation, and (c) Colin's personal reputation. That's a lot, and it costs money above the S3 storage costs (which you could point obnam at).
- vbit 13y ago
  Also, easier restore and snapshot deletion. Consider how you would restore using incremental ZFS snapshots. You'd have to pull all the snaphots, unpack the base snapshot and then sequentially unpack each incremental snapshot. In tarsnap, the server will compute the 'snapshot' you want for you, and will only send you the data blocks that belong to that snapshot. In tarsnap, you can also delete any snapshot you want, and only blocks belonging exclusively to that snapshot will be deleted. In your system, deleting a snapshot means you lose all snapshots from that one until the next full snapshot. Also, in ZFS you're limited to backing up complete datasets, but with tarsnap you can backup any set of files you want.

foobarqux 13y ago

I would like to do something similar with BTRFS. How are your snapshots incremental? In BTRFS you would need to specify a base snapshot. What is the restore process? You init a zfs file systems and then zfs receive the backups in chronological order? How are the dependencies between snapshots managed?

vbit 13y ago
The 'zfs send' command will send an incremental snapshot if you specify '-i snap1 snap2'. To restore, of course, you'll have to have snap1, and then you can apply the increment.
- foobarqux 13y ago
  That's what I thought. I wanted to know if the OP had some way to manage the dependencies between snapshots.

Nanzikambe 13y ago

To answer my own question: deduplication :) I had not considered multiple backup sources, mine is deduplicated per host, am I to understand tarsnap is deduplicated across all hosts sharing a set of keys?

beagle3 13y ago
I think that's the case. Note: https://github.com/bup/bup https://github.com/bup/bup does that too (though it does not encrypt), and http://liw.fi/obnam/ http://liw.fi/obnam/ does too (and it does encrypt). What tarsnap gives you that obnam doesn't is (a) managed cloud storage, (b) tarsnap's history and reputation, and (c) Colin's personal reputation. That's a lot, and it costs money above the S3 storage costs (which you could point obnam at).
vbit 13y ago
Also, easier restore and snapshot deletion. Consider how you would restore using incremental ZFS snapshots. You'd have to pull all the snaphots, unpack the base snapshot and then sequentially unpack each incremental snapshot. In tarsnap, the server will compute the 'snapshot' you want for you, and will only send you the data blocks that belong to that snapshot. In tarsnap, you can also delete any snapshot you want, and only blocks belonging exclusively to that snapshot will be deleted. In your system, deleting a snapshot means you lose all snapshots from that one until the next full snapshot. Also, in ZFS you're limited to backing up complete datasets, but with tarsnap you can backup any set of files you want.