[K12OSN] BackupPPC Question

Les Mikesell les at futuresource.com
Thu Apr 28 18:57:04 UTC 2005


On Thu, 2005-04-28 at 11:56, Henry Burroughs wrote:
> Les,
> 
> I was counting on you to respond to the BackupPPC question. ;-p  Thanks!
> 
> Now, do you store the backup data on the 250 gig IDE drive, or raid
> mirror the 3 external drives (how big are they)?  Could you give me a
> little more info about your setup.

Like I said, I'm not completely happy with mine so you may not want to
copy exactly.  The internal and external drives are basically identical
WD 250 gig IDE models.  For the first round of external drives I used a
firewire/usb case and installed the IDE drive myself.  I recently
replaced them with the pre-built external from WD (which still has the
same drive inside).  The only important thing about matching drives is
that the partition size would have to be set to the smallest member
if they weren't exactly the same.  All the drives have just one
partition, type 'FD'.   I created the RAID1 device with only the
internal drive and the other one specified as 'missing', then made a
reiserfs filesystem on it and mounted the md device as /opt/backuppc.
I already had a working configuration on a different machine so I
first installed backuppc, then copied most of the stuff other than the
archived backups over from there.  Once everything was up and running,
I added the mirror with 'mdadm /dev/md0 --add /dev/sda1'  (device
numbers may vary, of course) and the firewire drive was automatically
added to the raid.  You can watch the sync progress with 'cat
/proc/mdstat'.  It also works to shut the machine down, add a drive to
the ide cable and mirror to that instead of the external drive.  I did
that a few times when I was having trouble with my first set of drive
cases. So far I haven't gotten the system to automatically detect the
firewire drive at bootup in time to reconnect the mirror instead of
having to re-sync, but that hasn't been a problem.  The internal drive
is always seen as a 'broken' raid but works just as well anyway (that's
the point of raid1...).  I always do a 'service backuppc stop' and
unmount /opt/backuppc to make sure the filesystem is clean before
removing the firewire drive, but even if you didn't it should fix itself
from the reiserfs journal when you mount it again.  When adding a drive,
the sync happens *much* faster if there is no other activity so I try
to do that early in the morning so it will finish before starting
backups in the evening.  That might not work as well if you have
machines that are powered down at night so the backups have to run
during the day.

You might want to investigate SATA drives which are also available
in external cases.  These might be supported better than firewire now.
(Hmmm, maybe a Mac would work better with firewire...). FC1 didn't
auto-detect the device swap so there were several manual commands
involved and I'd generally end up rebooting after the swap. FC3 does
the auto-detect on a hotplug but not at bootup, and I've crashed a
couple of times with it (not immediately but always with the firewire
drive active in the raid). I've started to set up a ubuntu system to
see if it works better.  It does have the advantage of being able to
install backuppc with apt-get but I haven't had time to test much
else yet.

-- 
  Les Mikesell
   les at futuresource.com





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