Hello Experts,
I have a question about how does the PSP works. We have the below SATP list that should enforce EMC Symmetrix SAN to a default PSP of RoundRobin policy. Then i have decided to make a test of manually changing the LUNs multipath policy to Fixed then reboot the host to make sure it will come up and re-establish the LUN connection so it will apply the default PSP which is RR. However, it seems the default PSP was not applied and the LUN connection came up again as fixed with the same preferred path. Does anyone know if that's the expected behavior or if there is something wrong with my config? Below are the detailed steps. Thanks
[root@ESXi:~] esxcli storage nmp satp rule list | grep -i emc
VMW_SATP_SYMM EMC SYMMETRIX system EMC Symmetrix
VMW_SATP_INV EMC Invista system
VMW_SATP_INV EMC LUNZ system Invista LUNZ
[root@ESXi:~] esxcli storage nmp satp list
Name Default PSP Description
------------------- ------------- ------------------------------------------
VMW_SATP_SYMM VMW_PSP_RR Supports EMC Symmetrix
VMW_SATP_MSA VMW_PSP_MRU Placeholder (plugin not loaded)
VMW_SATP_ALUA VMW_PSP_MRU Placeholder (plugin not loaded)
VMW_SATP_DEFAULT_AP VMW_PSP_MRU Placeholder (plugin not loaded)
VMW_SATP_SVC VMW_PSP_FIXED Placeholder (plugin not loaded)
VMW_SATP_EQL VMW_PSP_FIXED Placeholder (plugin not loaded)
VMW_SATP_INV VMW_PSP_FIXED Placeholder (plugin not loaded)
VMW_SATP_EVA VMW_PSP_FIXED Placeholder (plugin not loaded)
VMW_SATP_ALUA_CX VMW_PSP_RR Placeholder (plugin not loaded)
VMW_SATP_CX VMW_PSP_MRU Placeholder (plugin not loaded)
VMW_SATP_LSI VMW_PSP_MRU Placeholder (plugin not loaded)
VMW_SATP_DEFAULT_AA VMW_PSP_FIXED Supports non-specific active/active arrays
VMW_SATP_LOCAL VMW_PSP_FIXED Supports direct attached devices
[root@ESXi:~]
Below is how the LUN looked like before change
[root@ESXi:~] esxcli storage nmp device list
naa.60000970000192605421533033423833
Device Display Name: EMC iSCSI Disk (naa.60000970000192605421533033423833)
Storage Array Type: VMW_SATP_SYMM
Storage Array Type Device Config: {action_OnRetryErrors=off}
Path Selection Policy: VMW_PSP_RR
Path Selection Policy Device Config: {policy=rr,iops=1000,bytes=10485760,useANO=0; lastPathIndex=2: NumIOsPending=0,numBytesPending=0}
Path Selection Policy Device Custom Config:
Working Paths: vmhba1:C0:T0:L3, vmhba1:C0:T1:L3, vmhba2:C0:T0:L3, vmhba2:C0:T1:L3
Is USB: false
i have then decided to manually change this LUN to fixed using this script that i have created. Below is an excerept of the script using PowerCLI
$lunpath =(get-vmhosthba -VMhost $vmhost -Type IScsi | get-scsilun $lun | get-scsilunpath | Where-Object {$_.State -like "Active"} | Where-Object {$_.Name -match "$device"} | Select-Object -first 1).Name
if ($lunpath){
Get-VMHost $vmhost | Get-ScsiLun $lun| Set-Scsilun -MultiPathPolicy Fixed -PreferredPath $lunpath
Below is how the LUN looked like after change, Fixed with a preferred path
[root@ESXi:~] esxcli storage nmp device list
naa.60000970000192605421533033423833
Device Display Name: EMC iSCSI Disk (naa.60000970000192605421533033423833)
Storage Array Type: VMW_SATP_SYMM
Storage Array Type Device Config: {action_OnRetryErrors=off}
Path Selection Policy: VMW_PSP_FIXED
Path Selection Policy Device Config: {preferred=vmhba1:C0:T1:L3;current=vmhba1:C0:T1:L3}
Path Selection Policy Device Custom Config:
Working Paths: vmhba1:C0:T1:L3
Is USB: false
I have then decided to reboot the host to make sure that as soon as it comes up, the ESXi will set the LUN PSP to RoundRobin as illustrated by the default PSP in the SATP list, however, i was surprised to find it still set to Fixed untill i manually changed it back to RoundRobin.
[root@ESXi:~] esxcli storage nmp device list
naa.60000970000192605421533033423833
Device Display Name: EMC iSCSI Disk (naa.60000970000192605421533033423833)
Storage Array Type: VMW_SATP_SYMM
Storage Array Type Device Config: {action_OnRetryErrors=off}
Path Selection Policy: VMW_PSP_FIXED
Path Selection Policy Device Config: {preferred=vmhba1:C0:T1:L3;current=vmhba1:C0:T1:L3}
Path Selection Policy Device Custom Config:
Working Paths: vmhba1:C0:T1:L3
Is USB: false
Does anyone know why the PSP did not change to the default RR policy after reboot? is there anything wrong with my config? Thanks
