[ubuntu] Software RAID1 - setting up on an already configured system

[soveryapt]

Ok, so I'm feeling a bit thick at the moment. Tying up loose ends at a school before I leave next week, and I seem to of left my planning head somewhere else.

 

Anyway, result of the above is that I have set up a new Ubuntu Server at the school (using 10.04 Desktop as they want a GUI interface to manage it as that is what the ICT Coordinator who will be looking after my role temporarily knows) and I meant to RAID1 it, however, I didn't.

 

It have got the system nicely configured doing all the usual bits and pieces a server should, so instead of starting again with it all, I wondered if there was a way to set up RAID1 without having to reinstall everything all over again.

 

Thanks from your local dunce in advance! lol ..

[dhicks]

I wondered if there was a way to set up RAID1 without having to reinstall everything all over again.

 

I've never had a problem restoring Ubuntu installs from a TAR file - simply tar up your new install on to a network share somewhere, reconfigure the disks however you like and un-tar your server on to the new volume. How exactly you go about making a RAID-1 software raid partition bootable is something you'll probably be able to Google.

 

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David Hicks

[soveryapt]

I've never had a problem restoring Ubuntu installs from a TAR file - simply tar up your new install on to a network share somewhere, reconfigure the disks however you like and un-tar your server on to the new volume. How exactly you go about making a RAID-1 software raid partition bootable is something you'll probably be able to Google.

 

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David Hicks

 

I shall try that if no one can think of another way round it.

 

I found How To Set Up Software RAID1 On A Running System (Incl. GRUB Configuration) (Debian Etch) | HowtoForge - Linux Howtos and Tutorials on Google, but when I come to the

 

sfdisk -d /dev/sda | sfdisk /dev/sdb

 

bit it says:

 

 

administrator@SERVER-001:~$ sudo sfdisk -d /dev/sda | sfdisk /dev/sdb
/dev/sdb: Permission denied

sfdisk: cannot open /dev/sdb read-write
Warning: extended partition does not start at a cylinder boundary.
DOS and Linux will interpret the contents differently.

 

[will_]

simply tar up your new install on to a network share somewhere, reconfigure the disks however you like and un-tar your server on to the new volume

Would that still work going from a non-RAID to a RAID filesystem? If not, you can probably still do something similar:

- Wrap up the old system in a tarball, omitting a few key directories that I can't remember at the moment but could find out if you like.

- Reinstall the OS with RAID.

- Unwrap the tarball over the new installation.

[will_]

Wrap up the old system in a tarball, omitting a few key directories that I can't remember at the moment but could find out if you like.

Found them. The things I exclude are:

/etc/hostname (although in your case it won't make much difference)

/proc

/lost+found

/mnt

/sys

 

EDIT: I can't find it in my documentation but I think I had to exclude /boot as well (when cloning to a different box in order to avoid references to a disk that doesn't exist).

Edited May 20, 2010 by will_
typo; omission

[soveryapt]

I can see this will be a fun time .. lol ..

[dhicks]

Wrap up the old system in a tarball, omitting a few key directories that I can't remember at the moment but could find out if you like.

 

tar seems to just ignore the bits it doesn't like the look of, so I just generally boot the system off SystemRescueCD (or similar), mount a network area to place the tar file in and the local harddrive you want to copy the install off, and just do something along the lines of:

 

cd /mnt/local
tar cf /mnt/network/file.tar *

 

I've actually wound up doing a bunch of Ubuntu / Debain VM installs like this - set up on a physical machine and then move over to a VM.

 

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David Hicks

[will_]

tar seems to just ignore the bits it doesn't like the look of

Interesting. I only excluded them because it failed when I didn't, but there you go; I suppose your mileage may vary!