Gary, See this wiki page, it explains how to import storage domains : http://www.ovirt.org/develop/release-management/features/storage/importstoragedomain/
Regards, Fred On Wed, Feb 15, 2017 at 10:15 PM, Nir Soffer <nsof...@redhat.com> wrote: > On Wed, Feb 15, 2017 at 9:30 PM, Gary Lloyd <g.ll...@keele.ac.uk> wrote: > > Hi Nir thanks for the guidance > > > > We started to use ovirt a good few years ago now (version 3.2). > > > > At the time iscsi multipath wasn't supported, so we made our own > > modifications to vdsm and this worked well with direct lun. > > We decided to go with direct lun in case things didn't work out with > OVirt > > and in that case we would go back to using vanilla kvm / virt-manager. > > > > At the time I don't believe that you could import iscsi data domains that > > had already been configured into a different installation, so we > replicated > > each raw VM volume using the SAN to another server room for DR purposes. > > We use Dell Equallogic and there is a documented limitation of 1024 iscsi > > connections and 256 volume replications. This isn't a problem at the > moment, > > but the more VMs that we have the more conscious I am about us reaching > > those limits (we have around 300 VMs at the moment and we have a vdsm > hook > > that closes off iscsi connections if a vm is migrated /powered off). > > > > Moving to storage domains keeps the number of iscsi connections / > replicated > > volumes down and we won't need to make custom changes to vdsm when we > > upgrade. > > We can then use the SAN to replicate the storage domains to another data > > centre and bring that online with a different install of OVirt (we will > have > > to use these arrays for at least the next 3 years). > > > > I didn't realise that each storage domain contained the configuration > > details/metadata for the VMs. > > This to me is an extra win as we can recover VMs faster than we can now > if > > we have to move them to a different data centre in the event of a > disaster. > > > > > > Are there any maximum size / vm limits or recommendations for each > storage > > domain ? > > The recommended limit in rhel 6 was 350 lvs per storage domain. We believe > this > limit is not correct for rhel 7 and recent ovirt versions. We are > testing currently > 1000 lvs per storage domain, but we did not finish testing yet, so I > cannot say > what is the recommended limit yet. > > Preallocated disk has one lv, if you have thin disk, you have one lv > per snapshot. > > There is no practical limit to the size of a storage domain. > > > Does Ovirt support moving VM's between different storage domain type e.g. > > ISCSI to gluster ? > > Sure, you can move vm disks from any storage domain to any storage domain > (except ceph). > > > > > > > Many Thanks > > > > Gary Lloyd > > ________________________________________________ > > I.T. Systems:Keele University > > Finance & IT Directorate > > Keele:Staffs:IC1 Building:ST5 5NB:UK > > +44 1782 733063 > > ________________________________________________ > > > > On 15 February 2017 at 18:56, Nir Soffer <nsof...@redhat.com> wrote: > >> > >> On Wed, Feb 15, 2017 at 2:32 PM, Gary Lloyd <g.ll...@keele.ac.uk> > wrote: > >> > Hi > >> > > >> > We currently use direct lun for our virtual machines and I would like > to > >> > move away from doing this and move onto storage domains. > >> > > >> > At the moment we are using an ISCSI SAN and we use on replicas created > >> > on > >> > the SAN for disaster recovery. > >> > > >> > As a test I thought I would replicate an existing storage domain's > >> > volume > >> > (via the SAN) and try to mount again as a separate storage domain > (This > >> > is > >> > with ovirt 4.06 (cluster mode 3.6)) > >> > >> Why do want to replicate a storage domain and connect to it? > >> > >> > I can log into the iscsi disk but then nothing gets listed under > Storage > >> > Name / Storage ID (VG Name) > >> > > >> > > >> > Should this be possible or will it not work due the the uids being > >> > identical > >> > ? > >> > >> Connecting 2 storage domains with same uid will not work. You can use > >> either > >> the old or the new, but not both at the same time. > >> > >> Can you explain how replicating the storage domain volume is related to > >> moving from direct luns to storage domains? > >> > >> If you want to move from direct lun to storage domain, you need to > create > >> a new disk on the storage domain, and copy the direct lun data to the > new > >> disk. > >> > >> We don't support this yet, but you can copy manually like this: > >> > >> 1. Find the lv of the new disk > >> > >> lvs -o name --select "{IU_<new-disk-uuid>} = lv_tags" vg-name > >> > >> 2. Activate the lv > >> > >> lvchange -ay vg-name/lv-name > >> > >> 3. Copy the data from the lun > >> > >> qemu-img convert -p -f raw -O raw -t none -T none > >> /dev/mapper/xxxyyy /dev/vg-name/lv-name > >> > >> 4. Deactivate the disk > >> > >> lvchange -an vg-name/lv-name > >> > >> Nir > > > > > _______________________________________________ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users >
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