On Thursday 24 March 2005 18:42, Ward... James Ward wrote:
> I like the idea of backing up to disk and then backing that backup onto
> tape say... weekly. I haven't used LVM under Linux so if I have to go
> that route, it will be new territory.
I use LVM2 on Linux since a few years. One of the uses is exactly for the
backuppc machine. We started using BackupPC on a spare machine (very old
indeed) with IDE disks grouped together into a 350G volume group.
It all worked ok until one morning when, coming to work I found the backuppc
processes stuck into a dump because of one of the IDE disks that failed
momentarily somehow. My biggest error was then to reboot the machine
(although I don't know now if I would have been able to do anything else, as
even killing the backupp processes wasn't possible).
When the system came back up, the LVM manager failed to restart the array,
even if the faulty disk seemed to have gotten healthy again. My only solution
was to rebuild the LVM volume from scratch, which effectively destroyed 6
months of backup.
Fortunately, that backup wasn't critical and luckily no backed-up machine
crashed during the first days after the incident (so that I didn't eventually
I wonder what is the experience people have with extracting data from LVM
volumes with partial/temporary disk (hardware) faults.
One nice trick I learned recently is building LVM on RAID. I thus prepare a
new machine for backuppc, with 2x400GB disks in RAID1, LVM added on top. This
ought to be a bit more resilient.
> I have approximately 2TB total maximum disk to back up (if every disk on
> every machine were 100% full. Is 1.75TB enough disk?
Depending on your network's typical usage and on your backup scheduling
configuration, backuppc should be able to "compress" your data up to 5 times.
I now have about 300GB of networked data backed up to an amount of about 2T
of full + incremental stores over the last 4 months, all this crammed in
about 160GB of disk space by backuppc.
Cristian Tibirna (418) 656-2131 / 4340
Laval University - Québec, CAN ... http://www.giref.ulaval.ca/~ctibirna
Research professional - GIREF ... ctibirna@...