----- "Augusto Castelan Carlson" <accarlson(a)gmail.com> wrote:
On 11/5/07, Richard W.M. Jones <rjones(a)redhat.com> wrote:
> The advantages of LVM when combined with virtualisation or Xen are
that
> you can create guest partitions easily and flexibly, that they can
have
> nice names, and that you can resize and also delete them simply.
LVM
> also lets you do this flexibly across physical disks, add extra
physical
> disks if you run out of space, and so on.
> So the basic command you need is:
>
> lvcreate -L 10G -n myguest VolGroup00
>
> which would create a 10 GB partition called /dev/VolGroup00/myguest
> within an existing volume group called VolGroup00. (This isn't
going to
> be a tutorial about LVM - there are plenty out there, go and use
Google).
>
> With the partition created above, just use the name of the
partition
> directly within the virt-manager creation dialog. Forthcoming
versions
> of virt-manager will be able to do the provisioning of LVM storage
more
> automatically. If you want to follow this work, take a look at
libvir-list.
>
> This doesn't address directly your problem "to be able to borrow
unused
> space from one guest to be used in another one". All that you'll
get
> with basic LVM is the ability to resize one guest down and another
guest up.
I pointed /dev/VolGroup00/myguest within virt-manager and installed
the guest.
Suppose that I need to add an extra physical disk or instead of
borrow, only resize one guest down and another guest up.
I did a lvextend to add 1G to myguest, but how can I make my guest
see
that change?
In lvm How To they use the command resize2fs to resize the
filesystem,
but I do not realize how to apply that changes to guests using LVM or
partitioned by the guest installer.
I tried to use the guest drive partitioned as /dev/xvda1 (boot),
/dev/xvda2 (/) and /dev/xvda3 (/home) and also with LVM.
How can I make the guest see that change?
If I understand... You created a LV called myguest in dom0 and within your domU you have
used fdisk to partition /dev/xvda and layered LVM on top of one of those partitions. Now
you've expanded myguest and want to see that space gain in the domU.
I think what you should have done is turn /dev/xvda into a PV inside your domU. At that
point you can use pvresize in your domU to take advantage of any space you may add to the
myguest LV in dom0. I'm not sure how you'd account for a change in /dev/xvda
otherwise. Someone else may know.
In your domU, you are working at the device level below the filesystem level. Resizefs
doesn't immediately come into play.
--
Dale Bewley - Unix Administrator - Shields Library - UC Davis
GPG: 0xB098A0F3 0D5A 9AEB 43F4 F84C 7EFD 1753 064D 2583 B098 A0F3