Hi,

I have a two controller Compellent system with two dual port 10g iSCSI front end cards in each controller (virtual ports enabled), I have tried a couple of different ways of configuring front end ports and I believe I have followed the MPIO best practices document correctly but I am unable to get MPIO working properly with my windows servers.

I have two 10g switches which are currently connected together, front end ports are all in one fault domain as follows:

10.0.10.1/25 Fault Domain Control Port

10.0.10.2/25 Controller 1 Card 1 Port 1

10.0.10.3/25 Controller 1 Card 2 Port 1

10.0.10.4/25 Controller 2 Card 1 Port 1

10.0.10.5/25 Controller 2 Card 1 Port 1

10.0.10.6/25 Controller 1 Card 1 Port 2

10.0.10.7/25 Controller 1 Card 1 Port 2

10.0.10.8/25 Controller 2 Card 1 Port 2

10.0.10.9/25 Controller 2 Card 1 Port 2

My servers (windows 2008r2) have dual port cards with a connection to each switch and ip's in the same subnet as the front end ports, MPIO feature is installed, iSCSI MPIO enabled and "COMPELNTCompellent Vol" added to Device Hardware ID's.

In the windows iscsi initiator control panel I add two entries for the discovery portal one for each local ip address both connecting to the fault domain control port.

Once the portals are added 8 targets are discovered, the names match the iqn shown on the virtual ports in storage center.

As per the best practices PDF I select each target in turn and create two connections, one from each local IP on the server, at this point the server connectivity tab in storage center changes status from partially connected to Connected.

To check the MPIO connections I selected one of the targets and click devices, select a device and click MPIO, 8 connections are listed, where I would expect to see 16 (8 x Front End Ports * 2 x Server Initiator Ports)

Selecting each target in turn and clicking devices I can see that only 4 targets have connections, and they are all virtual ports on controller 2, the connections to targets on controller 1 do not have any devices listed.

Performance is terrible, 0.2mb/sec benchmark using HD Tune Pro, if I change the MPIO Load Balance Policy to Round Robin With Subset and then set two paths as active (one from each server IP), performance is much better.

I have tried a different setup with two fault domains, two subnets, and isolated switches, and I have the same problem that once MPIO is enabled not all connections list devices and performance is terrible unless paths are manually changed to use only two paths.

How can I fix this?

Is it better to setup one fault domain for all iSCSI front end ports or to have one for each switch? The documentation I've read mentions both and I'm not sure which is the best choice for maximum performance and failover.

Andy