On Wed, Jul 19, 2017 at 09:24:56PM +0200, Stefan Wollny wrote:
> Hi there!
>
> Please excuse if this matter is not strictly OpenBSD-related even though
> I use OpenBSD.
That's OK, I happen to be the maintainer of archivers/p7zip, and also of
sysutils/shunt, which you may want to experiment with. Way back in the
old days when I backed up to CD and later DVD, I used shunt to split
backups into disc-sized chunks and burn them in the backup pipeline.
I haven't used it in years, but it should work for this purpose.
> When it comes to backups one usual advice (among others) is to make use
> of different storage types. So I have tar'ed one folder (~32GB) and
> zip'd with p7zip. man p7 explains the '-v{size}bkmg'-switch but I got
> "System ERROR: E_NOTIMPL".
I am unable to recreate this problem on amd64. I just used
$ vmctl create 100mb.file -s 100m
$ 7z a test.7z 100mb.file -v5k
I obtained 4 output files, test.7z.0001 thru test.7z.0004.
> ... Using split(1) I ended with several files of
> ~4.5GB each of which got burned to a DVD like so:
>
> $ doas growisofs -dvd-compat -Z /dev/rcd0c=<part-file>
This is your key problem. The ISO file in "<part-file>" needs to be
a CD9660/UFS file system when you use this form of the growisofs(1m)
command. Instead, it contains random compressed bits. This is why you
cannot mount it.
Practice burning with DVD-RW or DVD+RW media. You can continue to play
with it until you have your procedure correct, usable, and reproducable.
