Snapshots

Automation: Bulk Create and Delete VM Snapshots Across Linked vCenters | Lazy Admin Blog

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In a large environment, taking snapshots before a major patch or application update is a standard safety net. But if you have servers spread across multiple vCenters in Linked Mode (e.g., Datacenter1 and Datacenter2), clicking through the vSphere Client is a waste of time.

Today, I’m sharing a “Lazy Admin” script that allows you to bulk create, check, and remove snapshots using a simple CSV list.

Prerequisites

  • VMware PowerCLI: Ensure the PowerCLI module is installed on the machine running the script.
  • CSV Setup: Create a file named snapshot_servers.csv in C:\Temp\VMSnapshots\.

The CSV should look like this: | Host | Location | | :— | :— | | Server01 | Datacenter1 | | Server02 | Datacenter2 |

Part 1: Creating Snapshots

  1. Open PowerShell ISE with vCenter Administrator credentials.
  2. Load the functions by running the full script (provided below).
  3. Run the following command:
PowerShell
Create-VMSnapshots -SS_CSV "C:\Temp\VMSnapshots\snapshot_servers.csv" -SS_Name "Pre-Patching" -SS_Description "Requested by App Team"

The script will iterate through your CSV and create snapshots sequentially. You can monitor the progress in the vSphere Tasks console.

Part 2: Deleting Snapshots

Once your changes are verified, don’t let those snapshots linger and bloat your datastores! To remove them:

  1. Use the same snapshot_servers.csv list.
  2. Run the following command:
PowerShell
Remove-VMSnapshots -SS_CSV "C:\Temp\VMSnapshots\snapshot_servers.csv"

Note: This is a sequential script; it will wait for one snapshot removal to finish before moving to the next to avoid pinning your storage I/O.

The Script: VMSnapshots.ps1

Save this code to C:\Temp\VMSnapshots\VMSnapshots.ps1.

PowerShell
function Create-VMSnapshots { 
    param (
        [string]$SS_CSV = $(Read-Host "Enter path to CSV"),
        [string]$SS_Name = $(Read-Host "Enter name for snapshots"),
        [string]$SS_Description = $(Read-Host "Enter description for snapshots")
        )
    # Import VMware PowerCLI Module
    If ( !(Get-Module -Name VMware.VimAutomation.Core -ErrorAction SilentlyContinue) ) {
        import-module VMware.VimAutomation.Core
        }
    $Servers = Import-CSV $SS_CSV
    $WLM_vCenter = Connect-VIServer vCenter1 -WarningAction SilentlyContinue
    $EDN_vCenter = Connect-VIServer vCenter2 -WarningAction SilentlyContinue
    ForEach($Server in $Servers){
        If($Server.Location -eq 'Datacenter1'){
            New-Snapshot -VM $Server.Host -Name $SS_Name -Description $SS_Description -Quiesce -Server $WLM_vCenter -WarningAction SilentlyContinue
            }
        ElseIf($Server.Location -eq 'Datacenter2'){
            New-Snapshot -VM $Server.Host -Name $SS_Name -Description $SS_Description -Quiesce -Server $EDN_vCenter -WarningAction SilentlyContinue
            }
        }
    }
function Check-VMSnapshots {
    param (
        [string]$SS_CSV = $(Read-Host "Enter path to CSV"),
        [string]$SS_Name = $(Read-Host "Enter snapshot name")
        )
    # Import VMware PowerCLI Module
    If ( !(Get-Module -Name VMware.VimAutomation.Core -ErrorAction SilentlyContinue) ) {
        import-module VMware.VimAutomation.Core
        }
    $Servers = Import-CSV $SS_CSV
    $WLM_vCenter = Connect-VIServer vCenter1 -WarningAction SilentlyContinue
    $EDN_vCenter = Connect-VIServer vCenter2 -WarningAction SilentlyContinue
    ForEach($Server in $Servers){
        If($Server.Location -eq 'Datacenter1'){
            Get-Snapshot -VM $Server.Host -Name $SS_Name -Server $WLM_vCenter | Select VM, Name, @{ n="SpaceUsedGB"; e={[math]::round( $_.SizeGB )}} -WarningAction SilentlyContinue
            }
        ElseIf($Server.Location -eq 'Datacenter2'){
            Get-Snapshot -VM $Server.Host -Name $SS_Name -Server $EDN_vCenter | Select VM, Name, @{ n="SpaceUsedGB"; e={[math]::round( $_.SizeGB )}} -WarningAction SilentlyContinue
            }
        }
    } 
function Remove-VMSnapshots { 
    param (
        [string]$SS_CSV = $(Read-Host "Enter path to CSV")
        )
    # Import VMware PowerCLI Module
    If ( !(Get-Module -Name VMware.VimAutomation.Core -ErrorAction SilentlyContinue) ) {
        import-module VMware.VimAutomation.Core
        }
    $Servers = Import-CSV $SS_CSV
    $WLM_vCenter = Connect-VIServer vCenter1 -WarningAction SilentlyContinue
    $EDN_vCenter = Connect-VIServer vCenter2 -WarningAction SilentlyContinue
    ForEach($Server in $Servers){
        If($Server.Location -eq 'Datacenter1'){
            Get-Snapshot $Server.Host -Server $WLM_vCenter | Remove-Snapshot -Confirm:$false -WarningAction SilentlyContinue
            }
        ElseIf($Server.Location -eq 'Datacenter2'){
            Get-Snapshot $Server.Host -Server $EDN_vCenter | Remove-Snapshot -Confirm:$false -WarningAction SilentlyContinue
            }
        }
    }

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How to Change the Default Snapshot Location in VMware ESXi 5

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By default, VMware ESXi stores virtual machine snapshots in the same directory as the parent VM. If your primary datastore is running low on space, taking a new snapshot can fail or, worse, cause the VM to hang.

snapshot

Fortunately, you can redirect these snapshots (and swap files) to a different datastore with more “breathing room.”

Phase 1: vSphere Client Configuration

Before modifying files, we need to tell the VM not to store redo logs with the parent.

  1. Power OFF the Virtual Machine (This is mandatory for the changes to take effect).
  2. Right-click the VM and select Edit Settings.
  3. Go to the Options tab > General > Configuration Parameters.
  4. Click Add Row and enter:
    • Name: snapshot.redoNotWithParent
    • Value: true
  5. Click OK to save and exit.

Phase 2: CLI Configuration (.vmx Modification)

Now we define exactly where those snapshots should go.

  1. Log into the ESXi host via SSH or the local console.
  2. Navigate to your VM’s home directory:Bashcd /vmfs/volumes/[DatastoreName]/[VMName]
  3. Open the .vmx configuration file using the vi editor:Bashvi VMName.vmx
  4. Add the following line to the file, specifying your secondary datastore path:PlaintextworkingDir = "/vmfs/volumes/Secondary-Datastore/snapshots" (Press i to insert text, then Esc followed by :wq to save and exit.)

Phase 3: Reloading the VM

Changes to the .vmx file aren’t picked up until the VM is reloaded in the inventory.

  1. Find your VM’s ID:Bashvim-cmd vmsvc/getallvms | grep [VMName]
  2. Note the ID number (e.g., 13) and run the reload command:Bashvim-cmd vmsvc/reload 13

💡 Pro Tip: Keeping Swap Files in the Original Directory

By default, the workingDir parameter also moves the VM’s .vswp (Swap) file. If you only want to move the snapshots and keep the swap file with the parent VM for performance reasons, add this extra parameter in the Configuration Parameters (Phase 1):

Name: sched.swap.dir

Value: "/vmfs/volumes/Original-Datastore/VM-Directory"

#VMware #ESXi #StorageAdmin #SysAdmin #Virtualization #vSphere #TechTutorial #LazyAdmin #DataCenter #CloudComputing

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