This is the translated version of an article written in German originally. I translated it as a non-German speaking person has shown interest in the topic.

Disclaimer: This tutorial comes without warranty and support. Use at your own risk.

In this tutorial, I would like to show a minimal example on how selected VMDK files of specific VMs can be resized with using the PowerCLI.

This is useful, for example, when so many VMs are affected that the time and effort required to manually enlarge them via the vSphere (web) client seems too great.

Only the resizing of the VMDK file is considered here. The subsequent resizing of the partition and file system within the guest operating system, which is also necessary, is not part of this tutorial.

Goal

For a minimal example, from a group of VMs the second and third hard disk of VM-Test-5 and VM-Test-6 are to be enlarged. The respective second hard disk is to be enlarged from 250 GB to 500 GB and the respective third hard disk is to be enlarged from 400 GB to 800 GB.

Requirements

A working installation of the VMware PowerCLI and the ability to access the vCenter Server is a prerequisite to follow this tutorial.

Here we go

The following code block shows how the necessary information about the VMs is read out to be processed.

PowerCLI C:\Scripts> Get-VM | Where-Object {$_ | Select-String -pattern "VM-Test-\d"}

Name                 PowerState Num CPUs MemoryGB
----                 ---------- -------- --------
VM-Test-5        PoweredOn  4        24.000
VM-Test-7        PoweredOn  4        16.000
VM-Test-6        PoweredOn  4        24.000


PowerCLI C:\Scripts> Get-VM | Where-Object {$_ | Select-String -pattern "VM-Test-[5,6]{1}"}

Name                 PowerState Num CPUs MemoryGB
----                 ---------- -------- --------
VM-Test-5        PoweredOn  4        24.000
VM-Test-6        PoweredOn  4        24.000


PowerCLI C:\Scripts> $VM = Get-VM | Where-Object {$_ | Select-String -pattern "VM-Test-[5,6]{1}"}
PowerCLI C:\Scripts> Get-VM $VM | Get-HardDisk | FT Parent, Name, CapacityGB -AutoSize

Parent        Name        CapacityGB
------        ----        ----------
VM-Test-5 Hard disk 1         40
VM-Test-5 Hard disk 2        250
VM-Test-5 Hard disk 3        400
VM-Test-5 Hard disk 4         80
VM-Test-6 Hard disk 1         40
VM-Test-6 Hard disk 2        250
VM-Test-6 Hard disk 3        400
VM-Test-6 Hard disk 4         80

From the above output you can see that we want to enlarge the VMDK files which are called „Hard disk 2“ and „Hard disk 3“ respectively.

In the code block that follows, I first define a few variables, then double check that I am selecting the correct VMDK files for the operation, and then I resize them.

PowerCLI C:\Scripts> $HardDisk = 2
PowerCLI C:\Scripts> $HardDisk = "Hard disk " + $HardDisk
PowerCLI C:\Scripts> $HardDiskSize = 500
PowerCLI C:\Scripts> Get-HardDisk -vm $VM | where {$_.Name -eq $HardDisk}

CapacityGB      Persistence                                              Filename
----------      -----------                                                    --------
250.000         IndependentPersis... ...STD-2.9T-02] VM-Test-5/VM-Test-5_1.vmdk
250.000         IndependentPersis... ...STD-2.9T-01] VM-Test-6/VM-Test-6_1.vmdk


PowerCLI C:\Scripts> Get-HardDisk -vm $VM | where {$_.Name -eq $HardDisk} | Set-HardDisk -CapacityGB $HardDiskSize -Conf
irm:$false

CapacityGB      Persistence                                                    Filename
----------      -----------                                                    --------
500.000         IndependentPersis... ...STD-2.9T-02] VM-Test-5/VM-Test-5_1.vmdk
500.000         IndependentPersis... ...STD-2.9T-01] VM-Test-6/VM-Test-6_1.vmdk


PowerCLI C:\Scripts> Get-VM $VM | Get-HardDisk | FT Parent, Name, CapacityGB -AutoSize

Parent        Name        CapacityGB
------        ----        ----------
VM-Test-5 Hard disk 1         40
VM-Test-5 Hard disk 2        500
VM-Test-5 Hard disk 3        400
VM-Test-5 Hard disk 4         80
VM-Test-6 Hard disk 1         40
VM-Test-6 Hard disk 2        500
VM-Test-6 Hard disk 3        400
VM-Test-6 Hard disk 4         80


PowerCLI C:\Scripts> $HardDisk = 3
PowerCLI C:\Scripts> $HardDisk = "Hard disk " + $HardDisk
PowerCLI C:\Scripts> $HardDiskSize = 800
PowerCLI C:\Scripts> Get-HardDisk -vm $VM | where {$_.Name -eq $HardDisk}

CapacityGB      Persistence                                                    Filename
----------      -----------                                                    --------
400.000         IndependentPersis... ...STD-2.9T-02] VM-Test-5/VM-Test-5_2.vmdk
400.000         IndependentPersis... ...STD-2.9T-01] VM-Test-6/VM-Test-6_2.vmdk


PowerCLI C:\Scripts> Get-HardDisk -vm $VM | where {$_.Name -eq $HardDisk} | Set-HardDisk -CapacityGB $HardDiskSize -Conf
irm:$false

CapacityGB      Persistence                                                    Filename
----------      -----------                                                    --------
800.000         IndependentPersis... ...STD-2.9T-02] VM-Test-5/VM-Test-5_2.vmdk
800.000         IndependentPersis... ...STD-2.9T-01] VM-Test-6/VM-Test-6_2.vmdk


PowerCLI C:\Scripts>

If the above code block is not self-explanatory, feel free to post your questions about it in the comments. I’ll try to complete the tutorial in a timely manner.