topic Re: System Recovery in Operating System - Linux

System Recovery

Matthew Pegge_1 — Tue, 02 Jan 2007 05:36:20 GMT

What files if any should be excluded when restoring a system from bare metal (RHAS3 and 4) i.e. Rebuilt O/S from kickstart file to replicate partitions etc.. is there any files that should be excluded from the full restore? Are there any other gotchas when recovering servers with SAN attached storage?

Re: System Recovery

Huc_1 — Tue, 02 Jan 2007 06:49:43 GMT

I think you could exclude /proc /tmp
but best test this! for I have not

Jean-Pierre Huc

Re: System Recovery

Andrew Young_2 — Tue, 02 Jan 2007 07:44:51 GMT

Hi.

I would recommend that you build the OS as well and then exclude /dev /proc /tmp.

Just remember that you shouldn't mix RHAS3 and RHAS4 OS restores as they use different versions of LVM. In other words, don't do an OS restore of RHAS3 onto a kickstarted RHAS4 filesystem or vice versa.

In fact the best backup restore method would be to create a kickstart file from the original server, and keep all the latest RPM's. Then after the kickstart,all you would need to restore are /var, /home and /etc (and maybe /usr/local) and any other customised directories off the root. I would also restore /etc/sysconfig to another location and then mv the files as needed.

HTH

Andrew Y

Re: System Recovery

Matthew Pegge_1 — Tue, 02 Jan 2007 10:05:07 GMT

Thanks Guys,

We actually use RDP (altiris)to do the the initial system builds, which uses our standard ks.cfg file to create the filesystems and add all RPM's. So I'm fairly confident we can get the server to the same generic point.

However I was more concerned about what may or not have been added from the point the server is handed to the application teams. Some of these servers become Oracle others Websphere and so on.. and there is always the chance that extra RPM's have been added without proper change management, which was the reason for the restoration of / excluding /proc & /tmp.

Re: System Recovery

Andrew Young_2 — Wed, 03 Jan 2007 01:07:46 GMT

Hi.

Well then you should just need to add /dev to the exclude list.

Although Oracle is usually pretty good about keeping things in its own tree and I don't have any live Websphere sites any longer to check on those. However both use Java.

I would also not change /boot unless its really needed. If you have a spare blade or two I would suggest a few tests. The other thing to remember is that the WWN will change if you change blades so you may have to update your switches and possibly your configuration on your restored blade. I will try to update this in Feb when we do our testing on our blades.

Re: System Recovery

Matthew Pegge_1 — Wed, 03 Jan 2007 03:22:16 GMT

Thanks for your help! I'm about to start some tests today so will also update the post to let you know how I go! I'm starting with a non SAN attached blade then will move to SAN attached blades and DL's.

Thanks again!

Re: System Recovery

pjs_1 — Fri, 05 Jan 2007 08:30:52 GMT

If using RHAS 4 you should also exclude /selinux and /sys.