This is all covered in the vSphere Storage Guide which I will aim to summarise here. ESXi uses storage APIs known as the Pluggable Storage Architecture (PSA) to manage storage multipathing. Useful terms to understand in relation to PSA include:
- PSA – Pluggable Storage Architecture
- NMP – Native Multipathing Plugin
- PSP – Path Selection Plugin – Handles path selection
- SATP – Storage Array Type Plugin – Handles path failover for a storage array
The default NMP plugin provided by VMware has 2 sub-plugins – SATPs and PSPs. These are also provided by VMware, although there are also third party ones available. In addition, a third party may also make their own multipathing plugin available, which can replace VMware’s NMP. EMC PowerPath is an example of this.
Installing a PSA Plugin
As stated above, PowerPath is an example of a PSA plugin you may want to install. It’s recommended that you put the host into maintenance mode before installing the plugin. After downloading the PowerPath/VE trial, extract the contents of the zip file. You can download the software here. Once you have extracted the files, copy the locate the VMware zip file and secure copy the files to the host. You could also upload the files to a vMA or to another server with vCLI installed.
Place host in maintenance mode or move the VMs to another ESXi host then perform the installation by running: esxcli -s ESXiHostAddress software vib install -d /PathtoExtractedZipFileContents/index.xml:
/vmfs/volumes/4f27b82e-3fc1540e-bf6b-000c295da2d9/EMCPower.VMWARE.5.8.b342 # esxcli software vib install -d /vmfs/volumes/datastore1/EMCPower.VMWARE.5.8.b342/index.xml Installation Result Message: The update completed successfully, but the system needs to be rebooted for the changes to be effective. Reboot Required: true VIBs Installed: EMC_bootbank_powerpath.cim.esx_5.8.0.00.00-b342, EMC_bootbank_powerpath.lib.esx_5.8.0.00.00-b342, EMC_bootbank_powerpath.plugin.esx_5.8.0.00.00-b342 VIBs Removed: VIBs Skipped:
Once the install is complete you will need to reboot the host.
You can check out the plugin by running:
~ # esxcli storage core claimrule list Rule Class Rule Class Type Plugin Matches ---------- ----- ------- --------- --------- ------------------------------------ MP 0 runtime transport NMP transport=usb MP 1 runtime transport NMP transport=sata MP 2 runtime transport NMP transport=ide MP 3 runtime transport NMP transport=block MP 4 runtime transport NMP transport=unknown MP 101 runtime vendor MASK_PATH vendor=DELL model=Universal Xport MP 101 file vendor MASK_PATH vendor=DELL model=Universal Xport MP 250 runtime vendor PowerPath vendor=DGC model=* MP 250 file vendor PowerPath vendor=DGC model=* MP 260 runtime vendor PowerPath vendor=EMC model=SYMMETRIX MP 260 file vendor PowerPath vendor=EMC model=SYMMETRIX MP 270 runtime vendor PowerPath vendor=EMC model=Invista MP 270 file vendor PowerPath vendor=EMC model=Invista MP 280 runtime vendor PowerPath vendor=HITACHI model=* MP 280 file vendor PowerPath vendor=HITACHI model=* MP 290 runtime vendor PowerPath vendor=HP model=* MP 290 file vendor PowerPath vendor=HP model=* MP 300 runtime vendor PowerPath vendor=COMPAQ model=HSV111 (C)COMPAQ MP 300 file vendor PowerPath vendor=COMPAQ model=HSV111 (C)COMPAQ MP 310 runtime vendor PowerPath vendor=EMC model=Celerra MP 310 file vendor PowerPath vendor=EMC model=Celerra MP 320 runtime vendor PowerPath vendor=IBM model=2107900 MP 320 file vendor PowerPath vendor=IBM model=2107900 MP 330 runtime vendor PowerPath vendor=IBM model=2810XIV MP 330 file vendor PowerPath vendor=IBM model=2810XIV MP 65535 runtime vendor NMP vendor=* model=*
You can also install PowerPath using Update Manager, or include it as part of an custom image for use with AutoDeploy. You can read more about configuring plugins in this post.