Tugger the SLUGger!SLUG Mailing List Archives

Re: [SLUG] Backup theory

david <david@xxxxxxxxxxxxx> writes:

> I've got the following:
> 2 x servers - single small hard drives in each
> 1 x desktop - four hard drives including one removeable drive in a caddy
> intended solely for back up purposes.
> I run Mondo on the two servers periodically with the intention of
> being able to do a disaster [1] recovery quickly. Mondo produces 2 DVD
> images for each server. I run rsync nightly (good enough for my
> purposes) for more volatile data such as email, databases
> etc. Everything is very tidy.
> The desktop has about 350G of data and software. The software is
> unbelievably complicated because I use it to test server set-ups and
> odd bits of software etc. In other words, it's a dog's breakfast.
> I would like to run Mondo or something similar on this machine too,
> but I fear it would not be practical. At the moment I run rsync for
> the most obvious data, but that doesn't help with all the complicated
> software, and I would like to be able to recover that too in the event
> of disaster [1].
> What's the current best practice for back up in this kind of
> situation?

It varies.  Personally, I take advantage of the fact that a Linux system
has no magic "metadata", so a copy of all the files is enough to perform
a bare-metal restore.

I think use BackupPC[1] to provide me a space-efficient copy of all the
files.  In normal use the web interface is sufficient to recover from
most problems.

In a disaster I boot from a LiveCD, partition, format, etc, the disks,
and then use a combination of the command-line tar creation code in
BackupPC, netcat, and tar in the LiveCD to stream the data back over the

This is reasonably easy to achieve, but requires a little low level
knowledge of how partitioning, etc, work under Linux.  Mondo does
capture that information much more nicely, I confess.

> PS: On a Mac, you can usually take a hard drive out of one machine and
> put it in another and it will "just work". How much tweaking to get
> the same result on linux/ubuntu?

With a recent Debian or Ubuntu, zero.[2]  Getting X running again after
doing that /might/ take a bit of work, but not much, and the basic
system itself should be good.

If you use something less capable, like older RHEL systems, a fair bit
of work is required to get it booting, but the basic process is more or
less the same.

I don't know where Fedora sits, but I presume they have also moved more
to the Debian new-style "ship all the drivers in initramfs, detect the
hardware" strategy than the older RHEL "ship exactly what is required
for the current machine, hard code everything" model.


[1]  http://backuppc.sf.net/

[2]  Technically, you need to ensure the CPU architecture is compatible,
     so an x86_64 deployment will not run on an i386-only host, but
     otherwise you are good to go.