optionally support snapshot selection by ZFS creation date instead of name pattern

[sblive]

I'm really sorry if I missed it in the docs, but it would be awesome to optionally support snapshot selection by ZFS creation date instead of name pattern.
simple use case: vm backup shuts down VM and creates snapshot with e.g. "_clean" in it's name, but think many potential tags like this, so it would be necessary to call zfs-autobackup many times with all possible/impossible to guess suffixes/tags.

if enabled, this new flag would call e.g. something like zfs list -rtsnap -poname,creation to get all snapshots with their creation date and use that instead of pattern matching the name. it could still be useful to preselect snapshots by name, so there would be 3 cases:
*) existing selection by name
*) new selection by creation date
*) new selection by creation date, but filtered by pattern

thanks! :)

[psy0rz]

yeah i contemplated doing something like that, just using the creation date. But it also might lead to confusion. Also, after transferring it to the target, does it still have the same creation time?

[sblive]

using zfs list -poname,creation show different date for transferred snapshots (right now using current zfs-autobackup).
I realize your solution (comparing creation dates) would be "cleaner", but I was just proposing (1) an additional mode (2) selecting them by creation date and then (3) just checking if that name exists in target.
so the only (not very realistic IMHO) case it would "break" (not transfer snapshot), is if in the target (which should be a replication) there already exists a same named snapshot - i think this would be ok.

[psy0rz]

perhaps :)