[GTALUG] On the subject of backups.

[John Sellens]

On Wed, 2020/05/06 10:38:29AM -0400, Howard Gibson via talk <talk at gtalug.org> wrote:
| > ZFS is another option. And it handles delta-backups very easily.
| 
|    How do you recover stuff from delta backups?  You have to figure which backup the file or directory is in, right?

Remember that snapshots, like RAID, are not actually backups,
unless they are on a different machine, in a different place.

ZFS makes it easy:

You can browse through snapshots for /mypool/myfs by looking
in /mypool/myfs/.zfs/snapshot and if your ZFS snapshots are
named using dates, easy peasy to choose when.  You can also
brute force and
  find /mypool/myfs/.zfs/snapshot -name 'myfile.tex' -ls
and find what's there.

You can use "zfs rollback" to revert to a snapshot.

You can use "zfs send ... | zfs recv ..." to copy a specific
snapshot (or group of snapshots) to another pool, system, etc.

And of course, when you create a snapshot, you could create your
own index listing of what's there for easy grepping.

ZFS is great.

You can still (and likely should) continue to backup to Blu-ray,
but ZFS will make sure your files don't rot in place unnoticed.

Hope that helps, cheers

John