Multipath & Lock LUN

[Nick Gustafson]

I am planning a new 2-node cluster setup with multipath FC off a SAN for storage. According to the SG installation guide, we should not use multipath for the lock LUN. Is it possible to setup SG to use multipath for the lock LUN? Using a single path for the lock LUN sort of defeats the purpose of having multipath.

I'm using RHEL4 with GFS with 2x QLogic QLA2460 FC cards doing multipath off a EVA4000.

[Serviceguard for Linux]

Newer docs will be released soon that will (hopefully) make multipath support VERY clear.

We support the multipath that is provided by the QLogic driver. This is true for LockLUN as well as the the data LUNs.

We do not support MD multipathing for Lock LUN. There are no plans to ever provide that support.

We do not yet support DM multipath for LockLUN as it does not support some of the functions we need. If those functions are supported, we will test that function.

Our current plans are that the built in Emulex multipath function will be tested over the next couple of months.

While I'm explaining this, there is one other point I should probably make. If you do use the disk monitor, you will need to set SERVICE_FAIL_FAST_ENABLED=YES. This is do to a change in LVM where is does not deactivate a VG if it cannot access storage. This will be in the new docs as well.