Fault tolerance configure for DL165 and D2600

[Dermot1]

Hi,

I have two DL 165 G7 servers and a single D2600 disk array. At the moment the D2600 is directly atached to a single server using a P411 HBA. Is it possible to connect the d2600 to two separate servers? I have seen a document that shows a fault tolerant cable configration but it refers to a single host. What I am trying to achieve is if server A fails, that I can fall-over to server B and not lose access to the data stored on the D2600. Is such a configuration possible with this hardware?

I know that physically there is nothing to stop me plugging a SAS cable from each of the controllers on the D2600 but I am sure there would be more to it then that. The servers are running Ubuntu 12.

Thanks,

Dermot.

[David_Schwartzs · Accepted solution]

You can't with a D2600. The reason is that the intelligence is in the SmartArray P411 controller, and that server is maintaining the disk system.

You do have two options:
1) Manual failover - if you have a second server with a SmartArray controller, if the server ever failed, you could reboot the D2600 attached to the second server and be fine. RAID groups created by one SmartArray controller are recognized by other SmartArray controllers, allowing you to swap RAID drives between systems. HOWEVER, it should be noted there is a potential for data loss when moving an array from one controller to another if the controller cache hasn't been written back to disk completely, and this is not the best option.

2) Use a HP P2000 SAS-attached SAN. The HP P2000 has the intelligence in the controllers on the storage array, and does support use with clustering technologies such as Windows Cluster to do an active/passive type failover cluster. Because the P2000 has redundant controllers and the intelligence is in the storage box, I'd recommend this as the better solution.

Of course, there's higher end solutions that do more and more when it comes to redundancy, but I think this has been sufficient to answer I hope.

[Dermot1]

Thanks David.

I think option one will have to do then. The HBA was originally bought with a battery backed cache but that controller failed, was replaced and I am not sure if the new controller has one. However the data on the d2600 array is replicated data and not the original copy (the data is primarily video and stills). Funny enough, the original data is stored on a P2000 FC in our office.

Thanks for clearing that up. I will do some more reading on the P2000's capabilities. It will be useful.

Dermot.