[Rdo-list] Automatic resizing of root partitions in RDO Icehouse

[Kashyap Chamarthy]

On Tue, May 06, 2014 at 12:27:18PM -0430, Elías David wrote:
> Hi thanks for the answers!
> 
> But how is the support right now in OpenStack with centos/fedora images
> regarding the auto resizing during boot?
> does the disk size set in the
> flavor is respected or not, or does it work only with fedora and newer
> kernels than what CentOS uses...

I haven't tested it on CentOS, but looks like Shake Chen has confirmed
he's tested the resize feature (and reports that it works with ext4) on
his reply to this thread.

/kashyap

> On May 6, 2014 4:09 AM, "Kashyap Chamarthy" <kchamart at redhat.com> wrote:
> 
> > On Mon, May 05, 2014 at 10:22:26PM -0430, Elías David wrote:
> > > Hello all,
> > >
> > > I would like to know what's the current state of auto resizing the root
> > > partition in current RDO Icehouse, more specifically, CentOS and Fedora
> > > images.
> > >
> > > I've read many versions of the story so I'm not really sure what works
> > and
> > > what doesn't.
> > >
> > > For instance, I've read that currently, auto resizing of a CentOS 6.5
> > image
> > > for would require the filesystem to be ext3 and I've also read that auto
> > > resizing currently works only with kernels >= 3.8, so what's really the
> > > deal with this currently?
> > >
> > > Also, it's as simple as having cloud-init, dracut-modules-growroot and
> > > cloud-initramfs-tools installed on the image or are there any other steps
> > > required for the auto resizing to work?
> >
> >
> > I personally find[1] virt-resize (which works the same way on any
> > images) very useful when I'd like to do resizing, as it works consistent
> > well.
> >
> > I just tried on a Fedora 20 qcow2 cloud image with these below four
> > commands
> > and their complete output.
> >
> > 1. Examine the root filesystem size _inside_ the cloud image:
> >
> >     $ virt-filesystems --long --all -h -a fedora-latest.x86_64.qcow2
> >
> >     Name       Type        VFS   Label  MBR  Size  Parent
> >     /dev/sda1  filesystem  ext4  _/     -    1.9G  -
> >     /dev/sda1  partition   -     -      83   1.9G  /dev/sda
> >     /dev/sda   device      -     -      -    2.0G  -
> >
> > 2. Create a new qcow2 disk of 10G:
> >
> >     $ qemu-img create -f qcow2 -o preallocation=metadata \
> >       newdisk.qcow2 10G
> >
> > 3. Perform the resize operation:
> >
> >     $ virt-resize --expand /dev/sda1 fedora-latest.x86_64.qcow2 \
> >       newdisk.qcow2
> >     Examining fedora-latest.x86_64.qcow2 ...
> >     **********
> >
> >     Summary of changes:
> >
> >     /dev/sda1: This partition will be resized from 1.9G to 10.0G.  The
> >         filesystem ext4 on /dev/sda1 will be expanded using the 'resize2fs'
> >         method.
> >
> >     **********
> >     Setting up initial partition table on newdisk.qcow2 ...
> >     Copying /dev/sda1 ...
> >      100%
> > ⟦▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒⟧
> > 00:00
> >     Expanding /dev/sda1 using the 'resize2fs' method ...
> >
> >     Resize operation completed with no errors.  Before deleting the old
> >     disk, carefully check that the resized disk boots and works correctly.
> >
> > 4. Examine the root file system size in the new disk (should reflect
> >    correctly):
> >
> >     $ virt-filesystems --long --all -h -a newdisk.qcow2
> >     Name       Type        VFS   Label  MBR  Size  Parent
> >     /dev/sda1  filesystem  ext4  _/     -    10G   -
> >     /dev/sda1  partition   -     -      83   10G   /dev/sda
> >     /dev/sda   device      -     -      -    10G   -
> >
> >
> > Hope that helps.
> >
> >
> >   [1]
> > http://kashyapc.com/2013/04/13/resize-a-fedora-19-guest-with-libguestfs-tools/
> >
> >
> >
> > --
> > /kashyap
> >

-- 
/kashyap