[Linux-cluster] how to GFS+iSCSI failover?

[andremachado]

Hello,
I have 2 nodes (node_1, node_2) with 2 respective GFS (gfs_1, gfs_2) lvm exported trough iSCSI Enterprise Target to a third node node_3 with Open-iSCSI. 
What is the correct way to implement a cluster failover service to verify if node_1 becomes unavailable, 
umount/logout gfs_1 and then login/mount the gfs_2 from node_2 to the same mount point at node_3?

Should I configure a failover domain restricted, prioritized node_1 and node_2, each with a private resource gfs,
with THEIR local mount points or node_3 mount point?
Should I configure a resource custom script? (it seems likely).
How then monitor the node availability? 
could you explain the gfs, ip and script resources behaviour further than the RH docs?

Regards.
Andre Felipe Machado


updated [0] in June 21 2007

[0] http://www.techforce.com.br/index.php/news/linux_blog/red_hat_cluster_suite_debian_etch