topic Re: Dual MSA1000 controllers not interacting correctly in MSA Storage

Dual MSA1000 controllers not interacting correctly

CA1175041 — Thu, 26 Aug 2004 10:36:05 GMT

Hello All,
I have a MSA1500 cs StorageWorks shelf with dual MSA1000 controllers. They are currently not failing over to one another correctly. I have only two servers connected directly into their FC modules. Upon powering down the primary server connected to the primary controller it still holds the active state and the second controller continues to hold the passive state even though it is the only one connected. Has anyone experienced this problem before? I am assuming it is a redundancy sync issue or something. They seem to not be configured correctly. Thanks! I have also attached the show config for my secondary controller.

Re: Dual MSA1000 controllers not interacting correctly

Uwe Zessin — Thu, 26 Aug 2004 12:57:17 GMT

Hello Matt,

unfortunately the output is somewhat corrupted. It looks like you have not created any logical disks and this leaves portions of the storage array in an uninitialized state.

On the other hand ...
It sound like your cabling is not correct. You cannot connect one server single-path to controller-1 and the other server single-path to controller-2.

The MSA1500 with two controllers is currently limited to active/standby operations. That means that the active controller will handle all traffic to the logical disks.

The standby controller does announce the existence of logical disks so that any multipath software can work properly, but it does not re-route I/Os to the active controller like the VA7xx0 series storage arrays.

Re: Dual MSA1000 controllers not interacting correctly

CA1175041 — Thu, 26 Aug 2004 13:18:22 GMT

Thank you for responding Uwe.

I was curious about that. I recieved instruction from a CDW storage expert on this configureation. So, I need a SAN hub or switch to get this configuration workging, right?

Re: Dual MSA1000 controllers not interacting correctly

Uwe Zessin — Fri, 27 Aug 2004 04:37:38 GMT

Last time I checked, for two controllers you need dual fibre channel adapters in you servers, multipath software and dual switches or hubs.

Re: Dual MSA1000 controllers not interacting correctly

Stephen Kebbell — Fri, 27 Aug 2004 04:53:01 GMT

Hi Matt,

If you don't need redundancy, you could remove the 2nd MSA controller and FC I/O module and have it all single-path (with 1 switch)
I've attached a file with 2 drawings. One without and one with redundancy. Anything in between would not be a supported configuration.
Hope that helps.

Regards,
Stephen

Re: Dual MSA1000 controllers not interacting correctly

CA1201920 — Wed, 09 Nov 2005 15:00:18 GMT

Stephen,
Can one use your redundant scheme but only with one switch (no zones defined)? I realise that the switch would be an additional Single Point of Failure, but can it be done?

Re: Dual MSA1000 controllers not interacting correctly

BR894765 — Thu, 10 Nov 2005 13:40:14 GMT

You can use one switch by your own risk, but only zoned. One zone to main path, another--for redundant.