Subject: Re: backup: dump | gzip | cdrecord ?
To: None <email@example.com>
From: Wojciech Puchar <firstname.lastname@example.org>
Date: 08/26/2005 14:01:50
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> I'm looking for a way to backup to cd's/dvd's using dump(8). Searching
> through the archives, I found this post:
a bit upgrade what i wrote here with DVD's.
buy DVD+-RW recorder it makes 7x more space on really cheap media and..
it CAN be directly writable!!!
of course - it would be nice for dump to have and option of compression
and gzip, or at least pipethrough.
follow the instruction
1) unpack the attached file somewhere. should be exactly 32kB
2) buy DVD+RW media. DVD-RW may be used too, but i do prefer +RW. -RW
often makes errors at least in my case, while i have never problems with
+RW. price is near the same.
3) install dvd+rw-tools from pkgsrc
4) on fresh DVD+RW media do
on DVD-RW do
dvd+rw-format -force=full /dev/rcd0d
second will go through all disc but anyway it's OK
dd if=/path/to/DVDLABEL-RW of=/dev/rcd0d bs=32k
scsictl /dev/rcd0d flushcache
eject -l /dev/rcd0d
5) do dump with -a -b 64 and give /dev/rcd0a (not d!!) as tapefile.
when disc ends, do scsictl /dev/rcd0d flushcache
a) writing label and using a partition to DVD+-RW is mandatory. NetBSD
does not detect size of DVD+-RW media. this label looks like that
# size offset fstype [fsize bsize cpg/sgs]
a: 9180352 64 4.2BSD 0 0 0 # (Cyl. 0*-
d: 9180416 0 ISO9660 0 # (Cyl. 0 -
disklabel: partitions a and d overlap
b) scsictl /dev/rcd0d flushcache is mandatory, drive will refuse to eject
DVD or even may lock up without it. reading anything from drive makes the
same effect. anyway NetBSD kernel should do it on device close if at least
one write done.
c) at least at first usage verify should be done after backup
dd if=/dev/rcd0a bs=1m of=/dev/null progress=1
to make sure media isn't broken.
d) -b 64 is mandatory for DVD-RW media (can write in 32kB blocks), not
mandatory for DVD+RW media but anyway use it for better performance.
e) when using fresh DVD+RW media after flushcache you may not be able to
eject the disc. it's because DVD+RW in-drive background formatter works.
check the state with dvd+rw-mediainfo
f) no work with double layer DVD's if double later -+RW exist at all -
but should be OK after modifying the label file for right sizes.
Content-Type: APPLICATION/octet-stream; name=DVDLABEL-RW.gz
Content-Disposition: attachment; filename=DVDLABEL-RW.gz