Looking for a way to create an automated, and large number of DRS rules.

[AaronAnderson]

For example, I have a lot of machines named like this;

Fs001a

Fs001b

I need to create AntiAffinity rules to keep the the "a" and "b" machines on seperate hosts.

The rule created should be like "Fs001" and contain both machines.

New-DrsRule -Cluster Development -Name Fs001 -KeepTogether $false -VM Fs001a,Fs001b

Any direction/help with a powercli script that can do this would be greatly appreciated. I'm not sure how to handle name matching in powershell. This is something I would like to run as a scheduled job to avoid any human error in missed or incorrect rules.

[LucD]

Do the VM names always consist of 6 characters ?

[AaronAnderson]

No.

[LucD]

But they always end with 'a' or 'b' ?

[AaronAnderson]

The machines I want to create rules for will always end in 'a' or 'b' - but there are other machines that we don't want to touch.

[LucD · Accepted solution]

Try like this

Get-VM -Name *[ab] |
Group-Object -Property {$_ -match "(?<name>.*)[a|b]"; $Matches["name"]} | 
where {$_.Count -eq 2} | %{
    New-DrsRule -Cluster Development -Name $_.Values[0][1] -KeepTogether $false -VM $_.Group
}

Only when the script finds 2 matching names (one ends with a, and the other with b), will it create a DRS rule

[AaronAnderson]

LucD, that's a fantastic bit of code. Using some things in powershell that I wasn't familiar with. Thank you!

[AaronAnderson]

Is there any way to only fire the DRS creation if the rule name does not already exist? It seems that New-DrsRule allows duplicate rule names... not ideal. I assumed it would error out and I could ignore those.

[AaronAnderson]

I stood on the shoulders of smarter men than me, but I did it. Here's a version that can be run on a schedule and not create duplicate entries.

Clear-Host

$VCenterServer = server

$VMCluster = "Production"

Connect-ViServer $VCenterServer

# Stick current DRS rules into an array

$DrsRules = Get-DrsRule -Cluster $VMCluster

Get-Cluster $VMCluster | Get-VM -Name *[ab] |

Group-Object -Property {$_ -match "(?<name>.*)[a|b]"; $Matches["name"]} |

Where-Object {$_.Count -eq 2} |

ForEach-Object {if($DrsRules.name -notcontains $_.Values[0][1]){New-DrsRule -Cluster $VMCluster -Name $_.Values[0][1] -KeepTogether $false -VM $_.Group}}

[Revan5236]

The script looks great.  All our VMs end with av or bv, can the script be modified to do the same for our naming convention?

Thanks,

Michael

[LucD]

Try like this, it just needs a change in the Name parameter value and the RegEx pattern for the match operator.

$VCenterServer = server

$VMCluster = "Production"

Connect-ViServer $VCenterServer

# Stick current DRS rules into an array

$DrsRules = Get-DrsRule -Cluster $VMCluster

Get-Cluster $VMCluster | Get-VM -Name '*[ab]v' |

Group-Object -Property {$_ -match "(?<name>.*)[a|b]v"; $Matches["name"]} |

Where-Object {$_.Count -eq 2} |

ForEach-Object {

    if($DrsRules.name -notcontains $_.Values[0][1]){

        New-DrsRule -Cluster $VMCluster -Name $_.Values[0][1] -KeepTogether $false -VM $_.Group

    }

}

[Revan5236]

Thank you.  That works.

[Revan5236]

Is there a way to add -AB to the name of the rule that is created?  I've tried a couple different arguments, but my currently knowledge of powershell and powercli is lacking.  (reading and learning daily)

[LucD]

Like this ?

$VCenterServer = server

$VMCluster = "Production"

Connect-ViServer $VCenterServer

# Stick current DRS rules into an array

$DrsRules = Get-DrsRule -Cluster $VMCluster

Get-Cluster $VMCluster | Get-VM -Name '*[ab]v' |

Group-Object -Property {$_ -match "(?<name>.*)[a|b]v"; $Matches["name"]} |

Where-Object {$_.Count -eq 2} |

ForEach-Object {

    if($DrsRules.name -notcontains "$($_.Values[0][1])-AB"){

        New-DrsRule -Cluster $VMCluster -Name "$($_.Values[0][1])-AB" -KeepTogether $false -VM $_.Group

    }

}