[lug] LVM on RAID on Ubuntu

[David L. Anselmi]

durist at frii.com wrote:
> I'm about to upgrade my wife's Ubuntu 6.10 box to 7.10. It's currently running 
> on RAID1, but I'd like to add LVM on top of the RAID for flexibility. I've 
> spent a lot of time googling, but not found very much on this that seems to 
> be up to date.

It isn't hard as long as you keep your devices straight.

> 1) Can I put /boot and swap on LVM? 

Yes, I do.  I respect Sean's suggestion to put it on RAID-1 though.

> 2) For swap, is there a significant performance penalty?

Not for me.

> 3) Can I use grub, or do I have to use lilo? Is there any special 
> configuration I need to do?

Last I checked (over a year ago) you had to use lilo because grub 
doesn't understand the LVM format.  lilo just records disk blocks.  I'd 
guess Ubuntu handles lilo updates automatically when needed.

On Debian I sometimes have lilo problems if I've got a USB drive plugged 
in.  I usually rename them with udev so lilo complains that 
/proc/partitions lists sda and for me it shows up as usb/iomega-hd. 
Unloading sd-mod and running lilo fixes it, or unplugging the renamed thing.

> 4) Any special installation caveats or quirks of the Ubuntu installer I need 
> to know about?

Debian can install to LVM on RAID so I'd guess Ubuntu can too.  Even 
with the desktop installer you should be able to do that if you manually 
partition.  But I haven't done it.

Dave