Two iSCSI Portal IPs in separate subnets bound to separate NICs

[DPSGuard]

Hello Folks,

I am trying to setup FreeNAS 9.2.1.4 on a PC as iSCSI block storage, for MPIO access to my home study lab running two Hyper-V 2012R2 Nodes in a cluster (CSV). I have successfully set up two volumes (a small Quorum disk and one storage disk) thru one of the NIC. It all works great.

Now, I have added another NIC on separate subnet and added that IP address to existing portal so as to present the same two volumes. But on trying to discover / connect to this second portal IP address, thru Microsoft iSCSI initiator, I always get connection failure. I have reachability, tested via pings from the Hyper-V nodes.

Trying to create a new portal, then require a new target / extent, while I want to serve the same disks via to separate portals / NICs for resiliency and load balancing via MPIO.

Please advise and much appreciate.

 

[ser_rhaegar]

Did you install MPIO on your Hyper-V hosts?

 

[DPSGuard]

Yes, I have installed mpio role and has Microsoft dsm in it too. I tested it with starwind free SAN and mpio works great. I suspect there maybe more config needed on my freenas box than I could figure out. Is there a guide or link to such common setup?

Thanks so much.

 

[hammong]

Not 100% sure, but you might need two iSCSI NICs on your Hyper-V for it to do MPIO. I didn't have luck binding two IP addresses in two different subnets in Windows 2012 for the purpose of testing MPIO to two IP addresses on different subnets to Freenas. I needed two physically separate NICs - one plugged into each subnet.

My production environment actually looks like this: Freenas 9 server has 4 NICs for iSCSI, on FOUR separate IP subnets 192.168.100.0/24
192.168.101.0/24
192.168.102.0/24
192.168.103.0/24

Two of these subnets are set up as two VLANS on HP 1810g-24 switches. The "left half" of the switch ports 1-12 are assigned tagged as one VLAN, the "right half" of the switch ports are tagged for the second VLAN -- then I do the same thing with the other switch.

I have one Freenas 9 discovery group set up with the IP address of the Freenas box on each subnet.

Then, on the Windows 2012 MPIO side of things, I have a dual-port NIC dedicated to iSCSI with two IP addresses, 192.168.100.10 and 192.168.102.10 (note, two different subnets). Enabled MPIO driver, go to the discovery portal, and bingo - the volumes show up, and work as multi-path.

Catches to look for: In your Freenas iSCSI target configuration, make sure you have Allow Hosts entries appropriate for each subnet. E.g. for 192.168.100.0/24 subnet I have 192.168.100.0/24 as Allowed Hosts. This will ensure that only hosts on THAT subnet can access THAT target IP.

It should be that simple!

Greg

 

[DPSGuard]

Thanks Greg. Yes I have two NICs in each Hyper host dedicated to the iSCSI. But for MPIO load distribution, I need to connect each NIC to both Portal addresses / NICs. And in FreeNAS host, I had left default All allowed hosts. Good idea to restrict the hosts. Under windows MPIO, I had set up the initiators, under Discovery Tab, to talk to specific portal address under advanced set up option. I will look into it tomorrow again and it could be that I had missed a step. Appreciate your help.

 

[winterfrost]

I'm not sure if you ever found a solution for this, but I was having the exact same issue. But... while waiting for my FreeNAS forum account to get activated, I solved it. So, in case anyone else is having this issue, I thought I'd throw in the resolution to my issue, which sounded exactly the same.

Exactly the same as OP, I had iSCSI working fine between a FreeNAS box and two clustered Hyper-V servers in my lab. I added a second NIC on a separate subnet to all systems so I could set up MPIO. Added the second address to my existing portal. Everything continued to work great for first portal address, but any attempts to connect to the second address resulted in "Connection failed."

The step I missed: after adding the second address to the portal, I needed to restart the iSCSI service on the FreeNAS box. Did that and everything works!