On Thursday, April 07, 2016 07:47:59 AM Matthew Bohnsack wrote:
Hello.
I've been doing some experimentation with oVirt 3.6 and CentOS 7.2 hosts,
and I have a few high level questions, related to what I've seen in my
testing:
1/ It seems that for a given host, it's impossible to have both a local
storage domain and a shared storage domain such as NFS. Is this correct?
If so, is adding this capability on the roadmap somewhere? I would really
like to have the ability for a single host to simultaneously support both
local and network disks.
Storage is defined on a data center level, not on a host level, so you are
correct you cannot have local storage and shared storage in the same data
center.
2/ Does oVirt support any sort of live storage migration
functionality?
Yes, if you go to the disks main tab, you can select the disk you want to
migrate and click 'move'. This will give you a dialog that allows you to
select the target storage domain and profile.
2.A/ For example, say I have one host (host#1) with two separate
NFS
storage domains (NFS#1 and NFS#2). In this case, can a VM on host#1
associated with NFS#1 be live migrated to NFS#2 storage? Or can this sort
of storage movement only be accomplished by a shutdown of the VM and an
export/import/restart workflow?
2.B/ Is the scenario described in 2.A possible across two different hosts
that share both NFS storage domains? That is, can a VM guest on
host#1/NFS#1 be live migrated to host#2/NFS#2?
See above answer, you can live migrate between storage domains, and since
storage domains are at a data center level if both hosts are in the same data
center, and both storage domains are in the same data center, you can live
migrate the storage as well as the VMs. It will be 2 separate operations
though.
3/ Let's says that you setup a host (host#1) with a shared
storage domain
(NFS#1) and a second host (host#2) with a local storage domain (local#2).
If you wanted to move a VM from host#1/NFS#1 to host#2/local#2, how would
you most easily accomplish this? All I could come up with is: Add NFS
export domain to host#1, turn VM on host#1 off, export VM, add NFS import
domain to host#2, import VM, on host#2 onto local#2, turn VM on on host#2?
Since these hosts cannot be in the same data center (cannot mix shared and
local storage) that is the only option I know of for this particular scenario.
Thanks for your help,
-Matthew