DellEMC PowerPath / EMC Solutions Enabler / EMC Cluster Enabler Interfering with PURE LUNs
Overview
DellEMC PowerPath and Microsoft Windows Server MPIO, native Windows Device Specific Module (DSM), can co-exist on the same system for performing migrations between DellEMC Storage Area Network arrays, however it can interfere with Pure Based LUNs.
Also EMC Solutions Enabler and EMC Cluster Enabler that are DellEMC cluster management services and plugins, are known to prevent Pure LUNs from being successfully added as Cluster Shared Volumes (csv)
SITUATION 1: You Are Unable to Mount Pure LUNs To Hosts
How to Check if PowerPath is Attempting to Manage Pure Based LUNs
The following command can be used in PowerPath CLI to see if PowerPath is attempting to manage a Pure based Device.
powermt display dev=all
How to Persistently Unmanage Pure Devices from PowerPath Management
This process is not required for Windows native MPIO and PowerPath to coexist, but can be used if needed.
The following command can be used in PowerPath CLI to unmanage Pure devices reported in the process above from PowerPath management. This will prevent the powermt config command from re-adding the device to PowerPath.
powermt unmanage dev=<device>
The following command can be used to verify that the dev has been added to the unmanaged list in PowerPath.
powermt display unmanaged
SITUATION 2: You Can Successfuly Mount Pure LUNs To Hosts But Cannot Add To Cluster
Symptom:
- cluster.log shows PR reservation issues with Pure LUN such as (note the PR key a72a40d00001734d used by the cluster)
INFO [RES] Physical Disk <Cluster Disk 1>: Arbitrate - Node using PR key a72a40d00001734d ERR [RES] Physical Disk <Cluster Disk 1>: OnlineThread: Unable to arbitrate for the disk. Error: 2.
Recommended actions:
Please reach out to Pure Storage support to carry out additional troubleshooting on the storage end and provide further recommendations.