We need storage specifically for HPC Lustre failover setup, where it is must that two servers should share same block level storage to have failover configuration.
With very limited knowledge on hardware, I have the below understanding:
- NAS can be used for shared storage, but there will be bottleneck for speed due to intermediate network.
- SAN can be used, but it is costly to implement the solution and not really needed for Storage of 50-100TB.
- If at all we find multiple iscsi ports to the storage enclosure,
the storage can be used only by splitting i.e., works as two
storage devices and the same storage can't be used by both the
systems. (And one thing to remind here, in the lustre setup, both the servers would be only attached, but only one will be used (not sure, how it is possible, again need to check on this).
- Having two virtual machines may be how we can do it. But, then, it is not really helpful for the purpose of failover, as the physical machine would be only one.
But, while posting the question, I am thinking, may be we can compromise on speed in NAS, if we try having one directly attached server (primary) and the other attached via network (failover), so we face slowness only when the primary stops working.