Hello all,
I'm thinking about converting a couple of old dual Xeon V2
workstations into (yet another) oVirt setup.
However, the use case for this cluster is somewhat different:
While I do want most of the VMs to be highly available (Via 2+1 GFS
GlusterFS?
storage domain), I'd also want pin at least one "desktop" VM to each
host (possibly with vGPU) and let this VM access the local storage
directly in-order to get near bare metal performance.
This makes sense.
Now, I am aware that I can simply share an LVM LV over NFS / localhost
and pin a specific VM to each specific host, and the performance will
be acceptable,
This will not be fast as local device passed-through to the vm
It will also be problematic, since all hosts will mount, monitor, and maintain leases on this NFS storage, since it is considered as shared storage.
If another host fail to access this NFS storage the other host will be deactivated and all the VMs will migrate to other hosts. This migration storm can cause lot of trouble.
In the worst case, in no other host can access this NFS storage all other hosts will be deactivated.
I seem to remember that there's a POSIX-FS storage
domain that at least in theory should be able to give me per-host
private storage.
This is same as NFS (internally this is the same code). It will work only if you can mount the same device/export on all hosts. This is even worse than NFS.
A. Am I barking at the wrong tree here? Is this setup even possible?
This is possible using host device.
You can attach a host device to a VM. This will pin the VM to the host, and give best performance.
It may not be flexible enough since you need to attach entire device. Maybe it can work with LVM logical volumes.
Nir