Showing posts with label MPIO. Show all posts
Showing posts with label MPIO. Show all posts

Error message when adding MPIO Devices

In this case, Window Server 2012 Hyper V failover cluster LUNs were scheduled for storage migration from different vendors. Hyper V hosts were using fiber channel for accessing the SAN LUNs. These Hyper V hosts were using PowerPath as their multipathing software. This software was not recommended for use with the new SAN provider. So, after successful VM storage migration, PowerPath had to be removed, and Hyper V server hosts had to be configured with native MPIO.
After successful uninstallation of  PowerPath, I've tried to add MPIO devices using native MPIO tool, but there was error message "The system cannot find the file specified":


Similar error was prompt, when using the new powershell cmdlet for adding MPIO devices
New-MSDSMSupportedHW.

So, currently Hyper V server hosts were using single path for accessing the SAN LUNs, and obviously something went wrong with "successful" uninstallation of Powerpath. In order to create redundancy for SAN LUN access, I've reinstalled the MPIO feature on all Hyper v hosts.
After successful reinstallation of MPIO feature, I was able to add MPIO devices using native MPIO tool and enabled multiple paths for accessing SAN LUNs from Hyper V server hosts.
 

List MPIO disks active paths

This is a single liner PowerShell for listing active paths on MPIO disk devices:
(gwmi -Namespace root\wmi -Class mpio_disk_info).driveinfo | % {Write-host "Name: $($_.name) Paths: $($_.numberpaths)"}

Tested on Windows Server 2012 R2. This single liner should also work on other Windows Server editions.

And in case if there are multiple servers for checking the active paths on MPIO disk devices, here is the modified single liner (it's presumed that user running the bellow single liner owns the necessary permissions, and there are necessary firewall rules for accessing remote servers):
"server1","server2","server3" | % { write-host $_ -ForegroundColor green  ; (gwmi -ComputerName $_ -Namespace root\wmi -Class mpio_disk_info).driveinfo | % {Write-host "Name: $($_.name) Paths: $($_.numberpaths)"}}

Tested also on Windows Server 2016. 

How to check EMBG (Unique Master Citizen Number) using regex

In this post, I will share my implementation of how to check if some number looks like EMBG or Unique Master Citizen Number. For those of yo...