[libvirt-users] FYI: Notes on setting up KVM guests using iSCSI

[Tom Georgoulias]

On 05/05/2010 07:23 AM, Daniel P. Berrange wrote:
> DV suggested that we document some libvirt setups using shared storage. I'm
> not a fan of NFS, so I wrote some blog posts on how to use iSCSI in the
> context of libvirt + KVM.

Thank you for creating and sharing these.

>    http://berrange.com/posts/2010/05/05/provisioning-kvm-virtual-machines-on-iscsi-the-hard-way-part-2-of-2/

I have a question about this example, specifically the shareable 
permission option and tag:  (perm=sh, <shareable/>)

What does that do, exactly?  Is it simply the required r/w option to 
prevent corruption of VMs when using shared storage, or is it needed 
only if the disk will be actively by more than one VM?  (That 2nd idea 
doesn't seem quite right to me, I would expect to have to use some kind 
of locking technology to prevent it two or more VMs trying to write to 
the same disk at the same time).

Thanks,
Tom