[Linux-cluster] SCSI Reservations & Red Hat Cluster Suite

[Alex Kompel]

On Fri, Mar 28, 2008 at 8:15 AM, Ryan O'Hara <rohara at redhat.com> wrote:
>
> The reason for the cluster LVM2 requirement is for device discovery. The
> scripts use LVM commands to find cluster volumes and then gets a list of
> devices that make up those volumes. Consider the alternative -- users
> would have to manually define a list of devices that need
> registrations/reservations. This would have to be defined on each node.
> What make this even more problematic is that each node may have
> different device names for shared storage devices (ie. what may be
> /deb/sdb on one node may be /deb/sdc on another). Furthermore, those
> device names could change between reboots. The general solution is to
> query clvmd for a list of cluster volumes and get a list of devices for
> those volumes.

You can also use symbolic links under /dev/disk/by-id/ which are
persistent across nodes/reboots.

-Alex