MSA2012i Failover with One Controller

[herry78]

Hi Guys,

Just a quick one. Does MSA2012i single controller able to do failover in the event one port is failure?

As per my understanding, we need one controller to be failed before all failed volumes acessible from another controller. Is it true?

[Uwe Zessin]

Usually, you do present a volume to both host ports of a controller and set up multipathing on the host. In that case you can at least survive a simple port failure.

If the whole controller module fails, both ports go down and you lose access to the data on a single contrroller system.

[herry78]

Yep but still not understand on how the target could host the failed one.

My Setup on MSA2012i with single controller:
port0 192.168.1.20 Lun 0,1
port1 192.168.1.21 Lun 3

When unplugged port0, no problem with Lun No. 3. But what happen to Lun 0 & 1 then? Do port1 will host the port0 volume too?

[Uwe Zessin]

The MSA does not failover a volume between host ports of the same controller. You need to map the volumes which are behind LUN 0,1,3 to _both_ host ports so that the multipath component in the operating system recognizes both paths. Then, a host can even do I/Os to both paths.

[herry78]

Ok, will come back with the result later.

Thanks