topic Re: C3000 Connectivity for storage migration in BladeSystem - General

C3000 Connectivity for storage migration

1976NS — Wed, 13 Apr 2011 10:18:52 GMT

We have a C3000 + a number of BL490c G7s (half height). The C3000 has the following interconnects:

Bay1 – 6120XG

Bay2 – 6120G / XG

Bays 3/4 SAS interconnects

The blades have a dual onboard 10Gb adapter mapping to bay1, Mezz1 has a dual port 1Gb adapter mapping to bay2, mezz2 maps to bay3 and 4.

This is a 4 blade esx cluster and we are looking to migrate from SAS storage to 10Gb iSCSI.

My thought is to purchase a new 6120X to replace the SAS interconnect in bay3 which will remove the redundant path to the SAS array. I would then take down one esx blade and replace the card in mezz2 with an additional dual port 10Gb adapter. I think this would result in port one mapping correctly to bay3, however port2 would not connect as it would be connecting to bay4 which still has a SAS interconnect?????? Is this correct?

I would follow this procedure with all blades and cold migrate (over the network) all VMs to the new storage. Then I would have redundant 10Gb iSCSI paths, one through bay3 and one through bay1 – The network would have an 10Gb active path through bay1 and a 1Gb passive path through bay2.

Bay4 SAS interconnect would then be removed, however it would not be replaced due to cost with an additional 6120X.

I know this is not the best setup, however due to cost constraints this is the best approach for me. Can anyone see any potential issues in this setup, ie can I install the interconnect in bay3 whilst blades are trying to connect via SAS to it, also port2 of the dual port 10Gb adapter in mezz2 will be connecting to a SAS module for a short period, eventual connecting to nothing.

Re: C3000 Connectivity for storage migration

chuckk281 — Wed, 13 Apr 2011 16:50:04 GMT

I will get an expert to review and respond.

Re: C3000 Connectivity for storage migration

Stevem — Thu, 14 Apr 2011 03:02:27 GMT

No, this approach would not work. Mezz 2 wires 1 port to each Bays 3 and 4 as you know. If you remove the SAS switch from Bay 3 and insert a network switch, the switch would not start, as each server still has a SAS card installed, which connects to Bay 3. Same is true if you insert a NIC into Mezz 2 on a server and swapped out only 1 SAS switch, the server will not start, as one of the NIC ports (from Mezz 2) is connected to a SAS switch. You will get a Mezz card mis-match error.

I would suggest the following approach;

Remove the switchf from Bay 2 and replace it with a 6120XG and connect it to the network as the switch from Bay 1 is. Then, replace the Mezz card is Mezz 1 with dual port 10Gb NICs (NC552m would be good as it matches the same chipset as the base LOM).

Migrate the storage to LAN based storage and then later remove teh SAS switches and Mezz cards.

Re: C3000 Connectivity for storage migration

1976NS — Fri, 15 Apr 2011 08:16:31 GMT

Thanks for the response.

You suggestion is what I originally had in mind, however I read in the HP BladeSystem c3000 Enclosure Quick Setup Instruction that you cannot install a 10Gb card in mezz1, hence I could not use bay2?????