[CentOS] How to copy a system?

Thu May 5 22:50:29 UTC 2011
Les Mikesell <lesmikesell at gmail.com>

On 5/5/2011 4:22 PM, Dag Wieers wrote:
>> What I've really always wanted in this respect is something that would
>> work with backuppc [...]
> Well, I've become very fond of rbme as of lately, but since ReaR supports
> rsync out of the box, you don't need a separate backup method for it.
> But if backuppc has a client, or a configuration, it's very easy to make
> ReaR aware of it. And then to only configuration you would need to do is:

Backuppc usually doesn't need anything on the client side.  The server 
can run rsync or tar over ssh or use smb or talk to rsync in daemon 
mode.   It's basically a couple of perl programs to do the scheduling 
and provide a web interface wrapped around standard tools.  But, if you 
haven't used it, the thing it does better than any of the similar 
programs is that it compresses the files and pools all duplicate content 
with hardlinks so you can keep a much longer history of more hosts 
online than you would expect. It has an rsync-in-perl implementation to 
deal with local compressed files while chatting with a stock remote 
version. And it has a nice web interface to browse/restore files.  Or 
you can use a command line tool to generate a tar image.

> and it would automatically create a bootable image with your system's
> layout and the backuppc software/configuration, and even the necessary
> commands to automatically recover your system when doing:

I don't really want a separate copy of an 'image' built.  I want 
something to do the grunge work of partitioning and creating the 
necessary filesystems, then pull the tar image from the backuppc server 
with an appropriate ssh command.

>       rear recover
> on the rescue prompt. That's how it is done with Bacula, TSM, and others.

You could probably do something very similar by generating the tar 
image(s) ahead of time from the backuppc server and storing them in your 
recovery setup.  And that would be useful for archiving, offsite, or 
cloning purposes, but the main thing I want is the ability to boot 
something that can mindlessly reconstruct a machine from last night's 
backuppc run straight out of that compressed/pooled storage.

>> I already trust backuppc on the 'save a copy' side.   I'd rather not
>> replace that part.
> Does backuppc take care of restoring HWRAID, SWRAID, DRBD, LVM, paritions,
> filesystems ? If so, then ReaR may not be for you, because ReaR takes care
> of those items.

No, backuppc just saves files and can give you what looks like a tar 
image (or put them back if the target is working well enough to accept 
them).  That's why I'm interested in something else to do the work up to 
where you would restore a tar backup.  It's not extremely difficult to 
do by hand from a livecd boot, but automation is always better. 
Backuppc does handle the more common case of someone wanting a few files 
back that they accidentally erased very nicely and I don't want to do a 
whole different backup to cover rebuilding the machine.

>>> If you need more help, feel free to join the ReaR mailinglist on
>>> sourceforge and ask your questions :)
>> Would a backuppc adapter be feasible?
> Definitely, join the list and we can help you implement it.

OK, I'm interested...  It's probably just a matter of generating 
whatever description of the underlying storage it needs and plugging in 
an ssh command to get the data at the right point.

   Les Mikesell
    lesmikesell at gmail.com