For DataFabric Manager, we used Veritas to cluster 2 Linux hosts.
I used SnapDrive to create the LUN from one host, & then from another host issued a connect command.
From my experience I can list a few of the points to take care of
Basically if an application needs to be accessing the shared disk, then
1. Disable automatic startup of application during reboot on both the hosts
2. At any point only one host must be accessing the shared disk, so that data is not getting corrupted
You set the cluster server software to mount the shared disk on only one host at a time.
3. And before the application service is started, the DiskGroup & logical Volume must be enabled & disk mounted.
You can create a dependency tree, using cluster software.