Alan,
I have installed and config'd Service Guard a few times. The data disks are shared between systems with an exclusive "lock" which guarantees that only 1 node can access the shared disks at a time. The locking mechanism is LVM based. Specifically, only certified HP disks support the locking. Since the Netapps is an NFS Server, it is outside the scope of LVM and would not play well in a SG environment. NFS locks are 'advisory' - my process hopes your process adheres to pre-extablished rules.
Netapps has cluster configs which allow for redundancy of the filer and its DASD. This alone would be redundancy of DASD, where SG attempts to eliminate ALL single points of failure.
Another potential issue. NFS clients (HP-UX included) are not usually happy when the NFS server hangs, panics,... I worked on a SG environment where each node in the cluster was both a NFS client and NFS server to the other nodes. This sort of became a nightmare to implement.
HP has an NFS Toolkit for Service Guard which supports ONLY an NFS server, not the client.
On the other hand (the non-supported hand ;>) ), if you configured SG properly, the adoptive node (adopting the application during failover) would do an NFS mount to the filer and be able to access the data, if it were not corrupted. If you do decide to go ahead with this unsupported environment, I would be very interested in hearing the results.
Dave Mills Cypress Systems
-----Original Message----- From: Alan Beauchemin [mailto:Alan.Beauchemin.B@bayer.com] Sent: Thursday, March 30, 2000 8:22 AM To: - *toasters@mathworks.com Subject: NetApp and HP MC Service Guard
I have a project involving four HP systems requiring continuous availability. I would like to use MC Service Guard but I am not sure if I can use this software with a NetApp. Is anyone using this failover software in a NetApp / HP environment? I would also be curious of other methods of high availability from the server side with a NetApp?
Thanks Alan