Clusters and iSCSI failover

[Willybobs27]

I have a FAS 3140 cluster.

Luns on one head (Head A) are being presented to a Windows Server running SQL using iSCSI. No active LUNs are on Head B

Do I have to create iSCSI sessions / connections to the head (Head B) that doesn't run the live service to cater for Cluster Failover?

[radek_kubka]

Hi,

Do I have to create iSCSI sessions / connections to the head (Head B) that doesn't run the live service to cater for Cluster Failover?

Nope, that's not required. In a fail-over situation the remaining cluster head will take over 'virtual' identity of the failed head with its igroups, LUN mappings, etc.

But there are some caveats:

- NIC ports from both heads need to have access to the same subnets / VLANs

- Addresses of IP interfaces on Head A need to be manually specified in the config of Head B, so it can take over these IP addresses, should the failure occur.

Regards,
Radek

[BrendonHiggins]

Yes it does work but make sure your system is configured correctly first.  Download the HA Configuration Checker (cf-config-check.cgi) tool and test the config.  Even then it is best to take a 'pratice' before you do it with live data.  If your system is already in production, download the NetApp simulator and create a HA pair.  Then connect your iSCSI hosts to the VMs and begin testing.  This way you can confirm MPIO, IP routing and everything else is correct.

Hope it helps

Bren