[Users] Best practice to resize a WM disk image

[Karli Sjöberg]

ons 2013-01-09 klockan 09:13 -0500 skrev Yeela Kaplan:



----- Original Message -----
> From: "Karli Sjöberg" <Karli.Sjoberg at slu.se<mailto:Karli.Sjoberg at slu.se>>
> To: "Yeela Kaplan" <ykaplan at redhat.com<mailto:ykaplan at redhat.com>>
> Cc: "Rocky" <rockybaloo at gmail.com<mailto:rockybaloo at gmail.com>>, Users at ovirt.org<mailto:Users at ovirt.org>
> Sent: Wednesday, January 9, 2013 1:56:32 PM
> Subject: Re: [Users] Best practice to resize a WM disk image
>
> tis 2013-01-08 klockan 11:03 -0500 skrev Yeela Kaplan:
>
> So, first of all, you should know that resizing a disk is not yet
> supported in oVirt.
> If you decide that you must use it anyway, you should know in advance
> that it's not recommended,
> and that your data is at risk when you perform these kind of actions.
>
> There are several ways to perform this.
> One of them is to create a second (larger) disk for the vm,
> run the vm from live cd and use dd to copy the first disk contents
> into the second one,
> and finally remove the first disk and make sure that the new disk is
> configured as your system disk.
> Here you guide for the dd operation
> to be done from within the guest system, but booted from live.
> Can this be done directly from the NFS storage itself instead?
>

Karli, it can be done by using dd (or rsync), when your source is the volume of the current disk image
and the destination is the volume of the new disk image created.
You just have to find the images in the internals of the vdsm host, which is a bit more tricky
and can cause more damage if done wrong.


You mean since the VM's and disks are called like "c3dbfb5f-7b3b-4602-961f-624c69618734" you have to query the api to figure out what´s what, but other than that, you´re saying it´ll "just work", so that´s good to know, since I think letting the storage itself do the dd copy locally is going to be much much faster than through the VM, over the network. Thanks!
Will it matter if the disks are "Thin Provision" or "Preallocated"?




>
>
> The second, riskier, option is to export the vm to an export domain,
> resize the image volume size to the new larger size using qemu-img
> and also modify the vm's metadata in its ovf,
> as you can see this option is more complicated and requires deeper
> understanding and altering of the metadata...
> finally you'll need to import the vm back.
>
>
>
> ----- Original Message -----
> > From: "Rocky" < rockybaloo at gmail.com<mailto:rockybaloo at gmail.com> >
> > To: "Yeela Kaplan" < ykaplan at redhat.com<mailto:ykaplan at redhat.com> >
> > Cc: Users at ovirt.org<mailto:Users at ovirt.org> > Sent: Tuesday, January 8, 2013 11:30:00 AM
> > Subject: Re: [Users] Best practice to resize a WM disk image
> >
> > Its just a theoretical question as I think the issue will come for
> > us
> > and other users.
> >
> > I think there can be one or more snapshots in the WM over the time.
> > But
> > if that is an issue we can always collapse them I think.
> > If its a base image it should be RAW, right?
> > In this case its on file storage (NFS).
> >
> > Regards //Ricky
> >
> > On 2013-01-08 10:07, Yeela Kaplan wrote:
> > > Hi Ricky,
> > > In order to give you a detailed answer I need additional details
> > > regarding the disk:
> > > - Is the disk image composed as a chain of volumes or just a base
> > > volume?
> > > (if it's a chain it will be more complicated, you might want to
> > > collapse the chain first to make it easier).
> > > - Is the disk image raw? (you can use qemu-img info to check)
> > > - Is the disk image on block or file storage?
> > >
> > > Regards,
> > > Yeela
> > >
> > > ----- Original Message -----
> > >> From: "Ricky" < rockybaloo at gmail.com<mailto:rockybaloo at gmail.com> >
> > >> To: Users at ovirt.org<mailto:Users at ovirt.org> > >> Sent: Tuesday, January 8, 2013 10:40:27
> > >> AM
> > >> Subject: [Users] Best practice to resize a WM disk image
> > >>
> > >> Hi,
> > >>
> > >> If I have a VM that has run out of disk space, how can I
> > >> increase
> > >> the
> > >> space in best way? One way is to add a second bigger disk to the
> > >> WM
> > >> and then use dd or similar to copy. But is it possible to
> > >> stretch
> > >> the
> > >> original disk inside or outside oVirt and get oVirt to know the
> > >> bigger
> > >> size?
> > >>
> > >> Regards //Ricky
> > >> _______________________________________________
> > >> Users mailing list
> > >> Users at ovirt.org<mailto:Users at ovirt.org> > >>
> > >> http://lists.ovirt.org/mailman/listinfo/users > >>
> >
> >
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