Hi Mathieu,
On Wed, Sep 06, 2006 at 09:08:05AM +0200, Mathieu Avila
wrote:> Hello OCFS2 team,
>
> I'm currently looking at the OCFS2 code in linux-2.6.17.11, and i
wander
> why OCFS2 performs its heartbeat on a disk region unlike on the network
> like many clustered services stack do. What is the requirement for a
> disk heartbeat ? Is there any way to tune this behaviour and change it
> into a network heartbeat ?
The OCFS2 cluster stack heartbeats on both disk and network. Disk is
generally thought to have the final say as to whether a node is alive or
not. The reason we heartbeat on disk is because we want to be sure a
connection to the disk is maintained. Otherwise, the cluster could hang
indefinitely if the disk cable from one mounted node is unplugged - it
wouldn't be able to write out shared meta data for other nodes to read.
That all said, we're likely to remove the disk heartbeat in favor of a read
only mechanism in a future release of OCFS2.
--Mark
--
Mark Fasheh
Senior Software Developer, Oracle
mark.fasheh@oracle.com