[ovirt-users] Recommended setup for a FC based storage domain

[combuster at archlinux.us]

I need to scratch gluster off because setup is based on CentOS 6.5, so 
essential prerequisites like qemu 1.3 and libvirt 1.0.1 are not met.

Any info regarding FC storage domain would be appreciated though.

Thanks

Ivan

On Sunday, 1. June 2014. 11.44.33 combuster at archlinux.us wrote:
> Hi,
> 
> I have a 4 node cluster setup and my storage options right now are a FC
> based storage, one partition per node on a local drive (~200GB each) and a
> NFS based NAS device. I want to setup export and ISO domain on the NAS and
> there are no issues or questions regarding those two. I wasn't aware of any
> other options at the time for utilizing a local storage (since this is a
> shared based datacenter) so I exported a directory from each partition via
> NFS and it works. But I am little in the dark with the following:
> 
> 1. Are there any advantages for switching from NFS based local storage to a
> Gluster based domain with blocks for each partition. I guess it can be only
> performance wise but maybe I'm wrong. If there are advantages, are there any
> tips regarding xfs mount options etc ?
> 
> 2. I've created a volume on the FC based storage and exported it to all of
> the nodes in the cluster on the storage itself. I've configured
> multipathing correctly and added an alias for the wwid of the LUN so I can
> distinct this one and any other future volumes more easily. At first I
> created a partition on it but since oVirt saw only the whole LUN as raw
> device I erased it before adding it as the FC master storage domain. I've
> imported a few VM's and point them to the FC storage domain. This setup
> works, but:
> 
> - All of the nodes see a device with the alias for the wwid of the volume,
> but only the node wich is currently the SPM for the cluster can see logical
> volumes inside. Also when I setup the high availability for VM's residing
> on the FC storage and select to start on any node on the cluster, they
> always start on the SPM. Can multiple nodes run different VM's on the same
> FC storage at the same time (logical thing would be that they can, but I
> wanted to be sure first). I am not familiar with the logic oVirt utilizes
> that locks the vm's logical volume to prevent corruption.
> 
> - Fdisk shows that logical volumes on the LUN of the FC volume are
> missaligned (partition doesn't end on cylindar boundary), so I wonder if
> this is becuase I imported the VM's with disks that were created on local
> storage before and that any _new_ VM's with disks on the fc storage would
> be propperly aligned.
> 
> This is a new setup with oVirt 3.4 (did an export of all the VM's on 3.3 and
> after a fresh installation of the 3.4 imported them back again). I have
> room to experiment a little with 2 of the 4 nodes because currently they
> are free from running any VM's, but I have limited room for anything else
> that would cause an unplanned downtime for four virtual machines running on
> the other two nodes on the cluster (currently highly available and their
> drives are on the FC storage domain). All in all I have 12 VM's running and
> I'm asking on the list for advice and guidance before I make any changes.
> 
> Just trying to find as much info regarding all of this as possible before
> acting upon.
> 
> Thank you in advance,
> 
> Ivan