david <da...@kenpro.com.au> writes:
> Daniel Pittman wrote:
>> david <da...@kenpro.com.au> 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.
[...]
>>> 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.
>
> So this suggests to me that I could make a <# cp -a> of my root/boot
> drive onto an empty drive which I then remove and take off-site,
> rsync'ing it periodically?
Yes, that would be sufficient to provide a "bare metal" recovery copy of
your system.
> Or is it necessary to use dd?
Absolutely not.
> Where does the MBR fit into this?
Ah. Now, /that/ isn't part of the filesystem image, but is part of the
"partition, etc" part of the recovery process.
It is generally[1] sufficient to chroot into the restored system and
rerun the grub installer, or use the "fix the boot setup" option in your
rescue system.[2]
When I said that Mondo wrapped up some of this nicely, I meant that it
captures the partition map, LVM and MD configuration, and handles
reinstalling the boot loader after recovery.
None of that is strictly /hard/, but it is a set of things to learn how
to do, and something most people don't get a lot of practice in.
> The problem with any back up system is that normally you only find out
> that it works for sure when you really *need* it to work.
*nod* You know the *really* good thing about the widespread
availability of virtual machine software? "Free" bare metal to test
recovering systems to. :)
Regards,
Daniel
If you have a full copy of all your data, though, your worst case path
is "install a new system, copy the data back", so you can't loose /too/
badly.
Footnotes:
[1] As in, on any sane, modern platform, which definitely includes
current Debian and Ubuntu, but doesn't include RHEL 4 and, IIRC, 5
series systems. Unless your hardware is absolutely identical.
[2] I keep a grub boot CD in my "rescue" kit, since it can also be used
to reinstall the system, and it can read the existing menu.lst file.
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