iSCSI Multipathing - Really useful?

[fulvio6965]

Suppose to have this configuration:

2 ESXi host -> HP DL380 G7 (4 x 1 Gbit NIC + 2 x 10 Gbit NIC)

1 storage -> P2000 MSA (2 x 1 Gbit NIC + 4 x 10 Gbit NIC)

Both hosts will be connected to the storage through 10 Gbit adapter. Since no 10 Gbit switch is available, hosts will be DIRECTLY connected to storage.

Is Multipathing still needful in this case? I mean, as far as I can understand, Multipathing is very useful if you have multiple path to reach the storage (multiple switch with different network for examples). But in this case if for example a 10 Gbit card on one server will be lost, i would consequently lost both path.

Am I right? :smileyconfused:

[chriswahl · Accepted solution]

Is the 4 x 10 GbE NIC on the storage a single NIC? If not, you could cross over the cables from the hosts to it and have a safeguard from the perspective of the storage NIC dying.

Since I'm reading your post tos ay that all of the 2 x 10GbE NICs on the hosts are a single card, and if the storage 4 x 10 GbE NIC is also a single card, then the only reason to multipath would be to gain access to additional uplinks for better iSCSI throughput.

I would consider using the 1GbE NICs as a standby uplink to the 10GbE links to help prevent single points of failure.

[fulvio6965]

Answering your question: no on the storage we have 2 double 10 Gbit NIC = 4 x 10 Gbit NIC. So my idea is to cross cable to obtain that every host is connected to both storage cards.

Thank you for confirm me that multiphating offers better throughput!

[Morten_Dalgaard]

As the HP P2000 Storage system is a dual controller solution, you should preferably always connect your hosts with at least 1 path to each controller. This will safegaurd against controller failure, and let you upgrade the P2000's controller firmware without interruption of service.