Backing up to tape

[Polytropon]

On Thu, 26 Apr 2018 17:32:28 +0700, Olivier wrote:
> "Frank Leonhardt (m)" <frank2 at fjl.co.uk> writes:
> > I'll need a utility to save/restore ZFS datasets that are larger
> > than one tape if anyone knows of one. Otherwise I'll be writing
> > one, if anyone is interested.
> 
> While it should not be too difficult to design such a utility, you have
> to consider that each time you will want to access any data on the tar,
> you will have to stream through all the tapes, because tar format does
> not allow you to start with the tape 5 even if you know that the file
> you are looking for is not on the first 4 tapes.

In this case, pax is a convenient tool to deal with
multi-volume archives. It is part of the default OS
installation, of course. See "man pax" for details.



> It would be much better to split the data you want to tar, to have one
> set of data filling almost one tape.

Splitting the data beforehand probably is the best
way to deal with tar archives on tape. Maintaing a
"tape catalog" (usually automated) is a nice addition.



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...