[ovirt-users] vdsm without sanlock

[Devin A. Bougie]

Hi Nir,

On Nov 6, 2015, at 5:02 AM, Nir Soffer <nsoffer at redhat.com> wrote:
> On Thu, Nov 5, 2015 at 11:33 PM, Devin A. Bougie <devin.bougie at cornell.edu> wrote:
>> Hi, All.  Is it possible to run vdsm without sanlock?  We'd prefer to run libvirtd with virtlockd (lock_manager = "lockd") to avoid the sanlock overhead, but it looks like vdsmd / ovirt requires sanlock.
> 
> True, we require sanlock.
> What is "sanlock overhead"?

Mainly the dependence on a shared or remote filesystem (nfs, gfs2, etc.).  I have no problem setting up the filesystem or configuring sanlock to use it, but then the vm's fail if the shared filesystem blocks or fails.  We'd like to have our vm images use block devices and avoid any dependency on a remote or shared file system.  My understanding is that virtlockd can lock a block device directly, while sanlock requires something like gfs2 or nfs.

Perhaps it's my misunderstanding or misreading, but it seemed like things were moving in the direction of virtlockd.  For example:
http://lists.ovirt.org/pipermail/devel/2015-March/010127.html

Thanks for following up!

Devin