Fixed PSP

Creating the SATP Rule

Add the following SATP rule using the ESXi host’s console:

esxcli storage nmp satp rule add -V DataCore -M 'Virtual Disk' -s VMW_SATP_ALUA -c tpgs_on -P VMW_PSP_FIXED

Configuration Notes

• Hosts must have the ALUA setting enabled in the SANsymphony console. See Changing multipath or ALUA support settings for hosts.
• For Fixed PSP ESXi hosts must use the ‘All’ Preferred DataCore Server setting (see ‘Notes on choosing a preferred DataCore Server …’ below).
• If you are trying to modify an existing SATP rule, please follow the instructions on VMware Path Selection Policies.

The ‘All’ Preferred DataCore Server setting when using Fixed PSP
On using the ‘All’ setting
This will set all paths on all DataCore Servers to be ‘Active Optimized’ and while this may seem, at first, ideal it may end up causing worse performance than expected. When there is a significant distance between the DataCore Servers and the hosts (e.g., across inter-site links between remote data centers) then sending I/O Round Robin to ‘remote’ DataCore Servers may cause noticeable delays and/or latency.
Therefore, as the Fixed PSP requires the ‘All’ setting, testing is strongly advised before using Fixed PSP in production to make sure that the I/O speeds between servers is adequate. See Appendix A – Notes on Preferred Server and Preferred Path settings for more details using the ‘All’ setting.