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PowerShell | PowerCLI Snapshots & VM's

Proper snapshot management in VMware is essential to ensure efficient use of snapshots while avoiding potential issues that can impact performance, storage capacity, and overall VM stability. Here are key practices for effective snapshot management:

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  • Understand Snapshots:

    • Purpose: Snapshots capture the state of a VM at a specific point in time, allowing you to revert to that state if needed.

    • Hierarchy: Snapshots create a parent-child relationship. Each new snapshot creates a new child file linked to the previous snapshot or VM disk.

  • Snapshot Best Practices:

    • Use for Short-Term Needs: Snapshots are best suited for short-term use (e.g., before major changes or updates). Long-term use can lead to performance degradation and storage issues.

    • Regular Cleanup: Delete or consolidate snapshots promptly after they are no longer needed to avoid snapshot sprawl. Consolidation merges child disks back into the parent disk.

  • Monitoring Snapshots:

    • Regular Review: Monitor snapshot sizes and age regularly. Large or old snapshots can indicate potential issues.

    • Automation: Use scripts or tools to automate monitoring and alerting for snapshots nearing their intended lifespan or exceeding size thresholds.

  • Snapshot Creation and Deletion:

    • Clear Documentation: Document the reasons for creating each snapshot. This helps in determining when it can be safely deleted.

    • Scheduled Maintenance: Schedule regular maintenance windows to review and manage snapshots across your VMware environment.

  • Performance Impact:

    • Performance Considerations: Running on snapshots for extended periods can impact VM performance, especially on I/O-intensive applications.

    • Avoid Snapshots in Production: Minimize the use of snapshots on VMs hosting critical production workloads where performance is crucial.

  • Backup Integration:

    • Snapshots vs. Backups: Use snapshots as part of a backup strategy, but do not rely solely on snapshots for data protection. Regular backups to separate storage are essential for data integrity and recovery.

  • Emergency Procedures:

    • Snapshot Reversion: Understand the process of reverting to a snapshot and its impact on VM data. Test this procedure in a controlled environment to ensure it meets recovery requirements.

  • Educate Administrators:

    • Training: Ensure administrators and users understand the purpose and implications of snapshots. Establish guidelines and procedures for their use to maintain consistency and avoid misuse.

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By following these best practices, VMware administrators can effectively manage snapshots to improve system performance, maintain data integrity, and enhance overall VMware environment stability. Proper snapshot management ensures that snapshots serve their intended purpose without causing unforeseen issues or risks.

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PowerShell & PowerCLI
Check for Snapshots

$Computers=Get-VM | Select -ExpandProperty Name
Foreach($Comp in $Computers){Get-VM $Comp | Get-Snapshot | select VM, Name, Created, SizeGB, Description | Export-CSV C:\temp\All-Snaps-Review.csv -NoTypeInformation -Append
}

PowerShell & PowerCLI
Create Snapshots

$VMs=Get-Content C:\temp\Snaps\Snapper.txt

#Loop Through Updated List and Create Snaps before Patch Window
Foreach($VM in $VMs){
   Get-VM $VM | New-Snapshot -name "Pre-Patch Snap" -Description "Script Created-Prior to Patching" -RunAsync -ErrorAction Stop  
   Sleep 10
}

PowerShell & PowerCLI
Delete specific snapshot by name with 30 second interval

$Computers = Get-Content C:\temp\Snaps\One.txt
Foreach($Comp in $Computers){
    Get-Snapshot -VM $Comp | Where{$_.Name -eq 'Pre-Patch Snap'} | Remove-Snapshot -RunAsync -Confirm:$False 
    sleep 30
}
         

PowerShell & PowerCLI
Secure Boot Option

#Imports PowerCLI VMware PS Module

Import-Module VMware.VimAutomation.core

#Had to set this to connect to server

#Set-PowerCLIConfiguration -InvalidCertificateAction Ignore

#Connects to vCenter

Connect-VIServer VCENTERServerName

$vms=Get-VM | Where{$_.GuestID -like "*Windows2019*"}

Foreach($vm in $vms){

    $vm.Name

    $vm.extensiondata.config.bootoptions.efisecurebootenabled

}

PowerShell & PowerCLI
Stop-VM

$VMHosts=Read-Host "Enter VMHost"
Get-VMHost $VMHosts | Get-VM
$VMKILL=Read-Host "Enter VM Name"
Stop-VM -Kill $VMKILL -Confirm:$false

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