Re: [Xen-users] How do I resize a Physical Partition in a Dom U that's "
Bob Linkonij wrote:
> I'm not clear here - did you partition /dev/xvdc and create a filesystem on
/dev/xvdc1, or did you create a filesystem on /dev/xvdc ?
I'm pretty foggy about the xvdc vs xvdc1 name differences but if I
understand what you're asking I did the first type. I'm not even sure
how I'd do the latter, or if I should.
What does it say in /etc/fstab ?
If it has "/dev/xvdc" then the filesystem has been created in the
whole disk, which I think is easiest.
If it has "/dev/xvdc1" then the virtual disk has been partitioned and
the filesystem created inside the partition. How you would do that is
you would simply treat the virtual disk the same way as a real disk
and just partition it - from inside the guest.
Anyway I used Suse SLED v10's auto-installation stuff to do it. The
part of the script for the xvdc device was
Double dutch to me, but it does hint at having created a partition.
If you create a filesystem on the disk device rather than partitioning it,
then you can shutdown the guest, use resize2fs to enlarge the filesystem in
it, and startup the guest.
If you created a partition, then you will need to deal with that. I think
there was a discussion a while back on mounting partitions from a partition.
You'll need to enlarge the partition to fill the disk, and then you can
resize the filesystem in it. Other than doing it from within the guest I
don't know how to do that. Once you shutdown and then start up (NOT reboot)
the guest, it will see the new logical volume as a bigger disk - I don't
know if there is any way to make this happen 'live'.
So it sounds like the 1st one is simpler. And can be done live or hot.
Actually, it can't be done live - you have to unmount the filesystem
and fsck it before you can resize it. You'll struggle to unmount your
If you find that your root partition is /dev/xvdc1 then what I'd
suggest is this :
shutdown the guest
boot up another guest with this LV attached as a disk. This can be an
entirely different guest setup, or you could boot your current setup
from one of the "live cd" distros such as Knoppix.
You'll now be able to use fdisk to alter the partition - so you'll do
"fdisk /dev/xvdx" (where x is the current drive letter the LV gets
mapped to). I can't remember the commands, but there is one to alter
a partition, and you need to change the end of partition 1 (which
should be the only one) to be the end of the disk.
use resize2fs to expand the filesystem to fill the partition.
shutdown the guest, return everything to normal, boot up your guest
with the resized disk.
It's a lot easier to not use partitions in the guest. If you are
happy doing that, you could consider re-installing without using
partitions, but you may find it hard to persuade the installer to
accept that. IIRC, in Debian (whose installer I was using only today)
there isn't an option - but there may be a command line method to
bypass the disk partitions step.
For Xen guests, I usually just clone a basic image that was created
initially with debbootstrap - so I never use OS installers in a guest.
Maybe I should just redo the whole thing to use the "create a
filesystem on /dev/xvdc" way.
Any pointers on that one? I've tried to follow some of those
discussions, and just get lost. It seems like each message answers a
question someone's not asking.
That's often the way.
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