virtual grind thoughts from the virtual world

12Jun/110

Setting Default Path Selection Policy (PSP) – Round Robin

When using a storage technology such as Compellent, the ability to take advantage of multipathing is highly desirable. To utilize multipathing you must select the correct Path Selection Policy (PSP) on each ESX/ESXi host.

By default, the "Fixed (VMware)" path selection policy is selected on a new ESX/ESXi install. As you add volumes across multiple hosts in a cluster, this become a pain to change the path selection to "Round Robin (VMware)" on each volume on each host.

Fortunately, changing the default PSP is very easy with the following esxcli command:

esxcli nmp satp setdefaultpsp --satp="VMW_SATP_DEFAULT_AA" --psp="VMW_PSP_RR"

Please note that you want to first verify your "Storage Array Type" before setting the above policy. For Compellent, as of this post, the storage array type is "VMW_SATP_DEFAULT_AA". Other vendors may require a different type, such as "VMW_SATP_EVA" or "VMW_SATP_EQL".