[BBLISA] Recommendation for NAS appliance?

[Edward Ned Harvey]

> > ZFS send to the Dell, and from there backup to tape.
> 
> So out of curiosity, what format are your tapes? I recall reading some
> place that the ZFS send format is considered an internal format and may
> be subject to change (and hence shouldn't be used as the native format
> for archival purposes).

You read that from the man page, under "zfs send."  However, they've since
changed it - a few months ago.  For historical reasons, while they were
still figuring out how they wanted to format the "zfs send" datastream, they
stuck that comment in there.  But the older revs which included any
"incompatible" stream formats never made it into any solaris or opensolaris
release.  So it's relatively safe for you to assume, no matter how old your
OS release was, the zfs send datastream has always been, and always will be
compatible with newer versions.  Despite that comment in the man page, which
is now gone.

That being said, you still shouldn't use "zfs send" for archival purposes.
"zfs send" was meant to be streamed directly into "zfs receive" and not kept
on storage in between.  There are two major reasons:  (a) if a single bit is
changed in the "zfs send" datastream, then the whole archive is corrupt.
And (b) you can't restore a single file out of the middle of a "zfs send"
data stream.  You must receive the whole filesystem, or nothing at all.

If it's viable for you to backup to removable disks, then "zfs send | zfs
receive" is an excellent method of backup.  But if you need the backup on
tape, it's recommended to use some file-based backup tool that can handle
that.

To answer your question, we paid for Netbackup, so that's the tool that
writes our tapes.  I understand Amanda or bacula would be viable
alternatives for less than thousands of dollars, but I've not tried them.