Re: backing up a complete Debian GNU/Linux system
On Tue, Aug 03, 1999 at 06:25:28PM -0500, xxxxx xxxxx wrote:
> Hi! Could anyone tell me what's a good hardware/software combination to
> use to make frequent FULL backups of a Debian system (operating system,
> "applications", and data).
[...]
> I have thought about trying to use a CD-RW device, such as the HP 8100i or
> 8200i, but HP's web site seems to hint that you can't back up to multiple
> CDs in sequence, so that limits a backup to > 650 Mb.
[...]
We use a CDRW here at home to back up 4 systems on a network with tob
(backup script for afio) as packaged for Debian. Our backup requirements are
modest and fairly infrequent so the CDRW solution works fairly well (and
_lots_ better and cheaper than the Travan tapes we used to use). I've never
had to make backups larger than a CD (I seem to get about a 1Gb on a cd with
the compression) but multi-CD volumes should work. It would be a minor pain
to have to mount/unmount the CDs as afio worked through them on a restore
though.
The idea of using CDRW's to backup Debian systems seems to come up on a
regular basis so I'll take the liberty of posting a condensed version of the
method we use for all to tear apart.
We have a machine called krosno that doesn't get out much. In particular it
never has to do anything intensive enough to hurt a CDRW write session. It
used to be a 486/66 (worked OK with hdparm optimization). It's now a 75MHz
586 type (works OK). It exports a directory called /var/local/cdimage
read/write via NFS (Could be a security problem if bad people lurk on your
network. Would SSH's scp work?). The directory /var/local/cdimage/iso also
exists on krosno and must have at least 650 Mb free.
Each machine that needs to be backed up has tob installed on it with the
following lines in /etc/tob/tob.rc .
---------------------------------------------------------------------------
BACKUPDEV="/var/local/cdimage/iso/`hostname`_${VOLUMENAME}_${TYPE}.afio"
PRECMD='echo "mounting remote";mount -t nfs -o rsize=8192,wsize=8192 krosno:/var/local/cdimage /var/local/cdimage'
POSTCMD='echo "unmounting remote";umount /var/local/cdimage'
VOLMAX='650m'
BACKUPCMD='afio -o -s $VOLMAX -ZG9 -b10k $BACKUPDEV < $FILELIST'
BACKUPCMDTOSTDOUT='afio -o -ZG9 -b10k - < $FILELIST'
LISTCMD='afio -tv -s 0 -ZG9 -b10k /cdrom/*.afio'
RESTORECMD='afio -vin -s 0 -ZG9 -b10k -y"$FILESPEC" $BACKUPDEV'
---------------------------------------------------------------------------
After setting up the tob volumes as per normal, running tob produces a file
of the form /var/local/cdimage/iso/krosno_all_full.afio on krosno. You can
then run a script that invokes mkisofs and cdrecord on krosno to erase the
CDRW, write the contents of /var/local/cdimage/iso as a iso image to the
CDRW and erase the *.afio file. Repeat until the volume is entirely written.
The rescue disk only really needs afio and the ability to mount either an
normal iso cd image or nfs if the broken machine can't read a CDRW.
>
> Other considerations: ATX main system board, AMD k6-2 processor, WD 8.4Gb
> hard drive, and my need to have things work right - first time, every
> time, without exception.
[...]
Well 8.4 Gb is something like 8 CDRW's (compression depending). The
afio/compress/nfs/cdwrite cycle can take hours. Skipping the nfs writing
part and doing less intense compression would speed things up a lot but I
suspect that my CDRW solution is not for you if you want to back up the
entire 8.4 Gb every day. You'd have to settle for partial or less frequent
backups I think.
Bruce
Reply to: