HP MSA 2040 multipathing

[lasanthaj]

Hello everyone,

Recently we have purchased HP MSA 2040 FC SAN. SAN came with dual controllers. each controller has 4 ports. we have configured it  with 2 LUNs. currently we connected all controller ports (8) to two Brocade 300 SAN switches. after configuration VMware shows 8 path to particular LUN. we configured Round Robin as multipath policy. this is correct configuration ? if we use 8 paths it will give additional overhead to ESXI hosts ?

please share your ideas.

Regards,

Lasantha.

[rh5592]

Check with your Storage vendor for the recommended multipath policy. It will depend on your firmware as well as the version of ESXi you are using. ESXi host will detect your storage and and will set a preferred policy based on the defaults but it is best to check with your storage vendor, which in this case is HP.

If Round Robin is supported, it provides the best overall perfomance as it gives you load balancing between your paths.

[lasanthaj]

Hi Rommel,

Thanks for info. HP MSA 2040 support Round Robin. they also provide reference architecture for VMware . on that architecture design they only used single port on each controller . but we connected all port to Fabric switch. refer below image

                         in this setup We configured round robin. this will give additional bandwidth to SAN ?

[rh5592]

With Round Robin, what basically happens is by default 1000 I/O's will be sent to 1 path, then next 1000 I/O's to the next path, and so on... and such on a round robin fashion. I believe HP is recommending to change this setting from 1000 to 1. But I honestly dont know of the perfromance gain.

http://h20195.www2.hp.com/V2/GetPDF.aspx%2F4AA4-7060ENW.pdf

[lasanthaj]

Thanks Rommel

[Borja_Mari]

Hello,

as commented before, the best option is always checking the best practices of this SAN for Vmware.

HP for this SAN recommends using round robin with 1 I/O's

Based in my experience, using this configuration improves performance.

Best regards,

Pablo

[Didi7]

Hello everybody, according to the best practices for HP MSA2040 storage with VMware vSphere, HP recommends to set the iops Parameter for a LUN to 1 instead of 1000, when using Round Robin as Path Selection Policy.

Changing iops=1 with the following command under ESXi 5.5 Update 2 with ...

           esxcli storage nmp psp roundrobin deviceconfig set --type=iops --iops=1 --device naa.xxxxxxxxxxxxxxxxxxx

... results in the following output for a device ...

Path Selection Policy Device Config: {policy=iops,iops=1,bytes=10485760, ...}

Before setting iops to 1, the output was {policy=rr,iops=1000, ...}

Now, after setting iops to 1, the output is {policy=iops,iops=1, ...}

Do I make mistakes with the esxcli command or is the policy name always changed from 'rr' to 'iops' ???

Furthermore, I would like to know, if the iops setting can be changed on a LUN, which has VM directories with running VM's ???

Is a restart necessary to make the changes effective?

Regards,

Didi7