Target Server:
Windows Server 2012
Device - CDP Image, Thin Provisioned, Write-Through Caching (4096MB Cache Size)
Storage - 6 x 1TB WD Red in RAID 10 on PERC 6e (attached to Dell MD1000)
NIC - Intel i340 Quad GB: 10.250.0.10, 10.250.1.10, 10.250.2.10, 10.250.3.10
Initiator Server:
Windows Server 2012
Microsoft iSCSI Initiator
NIC: 2x Intel Dual GB: 10.250.0.11, 10.250.1.11, 10.250.2.11, 10.250.3.11
Server NICs are connected via 4 VLANs in an HP procurve switch - no flow control, no jumbo packets
Here is my issue. When I connect to the target with a single NIC, I see results I would expect (using ATTO Disk Benchmark):
Next, I add another target IP to discovery, enable multipath, verify I see two paths, Round Robin policy and run the same benchmark and see the improvement I would expect by adding another path:
Repeat with a third NIC:
Again, results get better with each NIC... until I add a 4th. After adding the 4th path my results plummet:
I've verified all the settings I can think of, but no matter what, when I add a 4th NIC to the mix, the results are half of what I'd expect with a single NIC. Hoping someone can help me understand why this happens?
Thanks,
EDIT: I apparently didnt check everything. for some reason, the 4th NIC on a quad port card is connecting at 100Mbps, so that definitely is the culprit. Well, typing it all out helped me find the issue in any case.
