[olug] Ubuntu home to RAID0

[Obi-Wan]

Thanks for the info.  LVM is not currently in use on the system.
The old /home is an ancient beast that probably predates the stable
use of LVM in Linux.  Just ext3 on a bare partition.

I definitely want striping on this new /home, not just JBOD.  I
feel the need... the need for speed.  I'm tired of waiting for my
hard drive to catch up with the rest of the system.

> I've done what you're trying to do. You should be able to do all of this
> as root on your live system.
> 
> You could just add the new disk space to the existing volume group,
> expand the logical volume then use resize2fs:
> 
> umount /home
> fdisk /dev/sdx into /dev/sdx1 (1TB) and /dev/sdx2 (.5TB)
> /sbin/pvcreate /dev/sdx1
> /sbin/vgextend VolumeGroup /dev/sdx1
> /sbin/lvextend LogicalVolume /dev/sdx1 <- adds the amount of space in
> /dev/sdx1 to LogicalVolume
> /sbin/resize2fs LogicalVolume
> mount /home
> 
> You don't get RAID0 with any of that though. Chances are the Ubuntu GUI
> utilities will do something similar.
> 
> Alternatively, you could remove /home from the LVM and use that space
> with the additional drive to make a RAID0 array:
> 
> umount /home
> lvremove -f the logical volume /home was stored on
> free up the PV with vgremove -f or vgreduce, depending on how your VGs
> are set up
> pvremove the physical volume
> mdadm --create /dev/md0 --raid-devices=2 --level=raid0 ...
> optionally put the RAID0 you just created into LVM with pvcreate,
> vgcreate/vgextend, lvcreate, etc
> mkfs.ext4 the new volume
> 
> On 7/13/2010 5:54 PM, Obi-Wan wrote:
> > Running Ubuntu 10.04 32-bit desktop.
> > 
> > OK, I've run out of space on my 1.0TB /home filesystem (separate drive).
> > I have another 1.5TB drive available, and I want to use 1.0TB of that
> > along with my old 1.0TB drive to create a striped (RAID0) 2TB partition
> > as the new /home.  I do NOT want to reinstall anything over my current
> > root drive.  The data on my old /home filesystem is already backed up
> > and therefore expendable.  I want the leftover 500GB on the second drive
> > to be available for some other purpose.
> > 
> > The catch is that I've seen the text-based commands for setting up LVM,
> > and it's enough to convince me that I *really* want to use a GUI utility
> > to handle the LVM setup for me.  Can I do that as root while wiping my
> > /home filesystem?  Can I do it while booted off my main root drive, or
> > must I boot off a live CD?
> > 
> > I need to do this ASAP.  Any pointers are appreciated.
> > 
> 
> -- 
> 
> Phil Brutsche
> phil at brutsche.us
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> 


-- 
Ben "Obi-Wan" Hollingsworth                             obiwan at jedi.com
   The stuff of earth competes for the allegiance I owe only to the
     Giver of all good things, so if I stand, let me stand on the
       promise that You will pull me through.  -- Rich Mullins