broadcom/qlogic npar isoe and MPIO policy on Windows 2012R2

Are you using HIT/Microsoft MPIO DSM?

Are you using single-port 10 GB arrays? 

If so, connections can default to 1 per member, and this can be modified in the MPIO DSM config on the Windows host.

Also, are you approaching the group/pool limitations for iscsi connection count? If so, connections could potentially be automatically scaled down - to allow other potentially at-risk volumes to remain online.

Hi,

Yes, HIT KIT version 4.9 is installed. 

There are 2 x10GbE -eth0&1 on 6210 and both are active. There is only 1 member in the group and couple of hosts (3 servers) are connecting to the array. 

MPIO connection settings are default on HIT KIT which are; max sessions per entire volume 6 , max sessions per volume slice 2

I'll go through the documents to see if I miss anything before simulating network/nic failure. I'll post my findings as well.

thanks,

You should not use Teaming on the NICs that you are using for iSCSI MPIO.

Also - ensure that the Server's SAN interfaces are appropriately included in the MPIO DSM configuration.  On the same token, ensure that the non-SAN interfaces are excluded from the MPIO DSM configuration.  This can be managed via ASM/ME or the PowerShell Tools.

Hi Michael,

Each CNA on the server is configured like 

• partition 0 ; iscsi enabled, ethernet and fcoe disabled
• partition 1; ethernet enabled, iscsi and fcoe disabled
• partition 2 and 3 all disabled

So I dont use nic teaming for partiton 0 and as this partition is listed as storage hba can only be configured through BASP/Qlogic Control Suite. So I've just enabled jumbo frame (9600 as recommended) and assigned ip address from the storage network.

Partition 1 however is configured with Microsoft Teaming (2012r2 builtin) with dynamic + switch independent mode for LAN/Server ( non-storage) traffic. 

On the hit kit, I've already excluded all other subnet as you mentioned.

"ensure that the Server's SAN interfaces are appropriately included in the MPIO DSM configuration."  I'm not quite sure if you are asking this, storage subnet is already included on Dell ASM/HIT kit and both partition 0 interfaces are in the same subnet. Please let me know if you need more details.

Thanks,

If after making those changes, you're still having issues, I'd recommend that you open a Support case.  Best of luck.

Hi Don,

" A cable or switch failure will not bring down your volume.   If the load goes up another connection will be established. " 

Thanks for details that you provided however I've noticed losing active path actually causes operating system lost disk/lun connection as the second path never reestablishes/reconnects.

The whole idea using NIC partition and enabling isoe was to make sure DCB is configured all the way through (storage-switches-server). Based on my research the easiest way to configure DCB on the operating system (windows 2012r2) is to let CNA deal with it through enabling isoe.

 Unfortunately I've been told;

1. this is not very common setup even though is published in one of the best practice guide
2. having 2 (isoe adapter) initiator adapter accessing to same group ip (discover portal on MS initiator) somehow is not working well with EQL MPIO. 

As you mentioned, EQL MPIO will not bring much difference in terms of performance so I'll try with MS native MPIO to see if both paths are active and survive during the network/switch outage.

Thanks,