2,187
edits
(→Error Hints: Minor update) |
(→Storage: Added PSP) |
||
Line 206: | Line 206: | ||
* <code> Disk.UseLunReset </code> set to <code> 1 </code> | * <code> Disk.UseLunReset </code> set to <code> 1 </code> | ||
* <code> Disk.UseDeviceReset </code> set to <code> 0 </code> | * <code> Disk.UseDeviceReset </code> set to <code> 0 </code> | ||
=== Path Selection Policy (PSP) === | |||
* Active-Active (AA) - Storage array allows access to to LUN's through all paths simultaneously. | |||
* Active-Passive (AP) - Storage array allows access to to LUN's through one storage processor at a time | |||
* Asymmetric (ALUA) - Storage array prioritises paths available to access a LUN (See http://www.yellow-bricks.com/2009/09/29/whats-that-alua-exactly/) | |||
{|cellpadding="2" cellspacing="0" border="1" | |||
|- style="background-color:#bbddff;" | |||
! Policy !! For Arrays !! Description | |||
|- | |||
| Most Recently Used (VMW_PSP_MRU) || All (default for AP arrays) || ESX uses whatever path is available, initially defaulting to last used or first detected at start up | |||
|- | |||
| Fixed (VMW_PSP_FIXED) || Active-Active (not for AP) || ESX uses preferred path, unless its not available. Can cause path thrashing with AP arrays | |||
|- | |||
| Fixed AP (VMW_PSP_FIXED_AP) || All (though really for ALUA) || As for Fixed, but the ESX picks the preferred path, and uses path-thrashing avoidance algorithm | |||
|- | |||
| Round Robin (VMW_PSP_RR) || All || ESX uses all available paths (will be limited by AP arrays) | |||
|} | |||
= Procedures = | = Procedures = |