Checking for any snapshots running on VMs in various clusters can be quite repetitive if done manually, looking through vCenter at each of your VMs. In the clusters I work with there are a LOT of VMs to check, and naturally I wanted to automate this process. Sure, I could rely on the vCenter alarms for snapshot size warning, but these are not completely reliable, as they only alert me when snapshots start growing large in size. I wanted something that would alert me to the presence of a snapshot regardless of its size. I therefore set about learning the basics of PowerCLI (as you can see in my last post) and searched around for some sample cmdlets that would help me retrieve a list of VMs with snapshots on them.
So here is the end result of running this snapshot checking script. It uses powershell cmdlets to generate an HTML email and sends it across to the address you specify. You will of course need to ensure you can connect out on port 25 for mail and have authentication on your mail server (or being sending from and to a domain hosted on your mail server (i.e. connecting to relay mail internally). Enter your mail server, to, and from details in the script to customise it. You’ll also need to authenticate with your vCenter server before running the script of course – you could use a cmdlet in the script to do this automatically. I have just been manually authenticating for now as I have not yet deployed this in production and have just been testing.
So here is the all important PowerCLI script!
#These are the properties assigned to the HTML table via the ConvertTo-HTML cmdlet - this is used to liven up the report and make it a bit easier on the eyes!
$tableProperties = "<style>"
$tableProperties = $tableProperties + "TABLE{border-width: 1px;border-style: solid;border-color: black;}"
$tableProperties = $tableProperties + "TH{border-width: 1px;padding: 5px;border-style: solid;border-color: black;}"
$tableProperties = $tableProperties + "TD{text-align:center;border-width: 1px;padding: 5px;border-style: solid;border-color: black;}"
$tableProperties = $tableProperties + "</style>"
# Main section of check
Write-Host "Looking for snapshots"
$date = get-date
$datefile = get-date -uformat '%m-%d-%Y-%H%M%S'
$filename = "F:\VMwareSnapshots_" + $datefile + ".htm"
#Get your list of VMs, look for snapshots. In larger environments, this may take some time as the Get-VM cmdlet is not very quick.
$ss = Get-vm | Get-Snapshot
Write-Host " Complete" -ForegroundColor Green
Write-Host "Generating snapshot report"
$ss | Select-Object vm, name, description, powerstate | ConvertTo-HTML -head $tableProperties -body "<th><font style = `"color:#FFFFFF`"><big> Snapshots Report (the following VMs currently have snapshots on!)</big></font></th> <br></br> <style type=""text/css""> body{font: .8em ""Lucida Grande"", Tahoma, Arial, Helvetica, sans-serif;} ol{margin:0;padding: 0 1.5em;} table{color:#FFF;background:#C00;border-collapse:collapse;width:647px;border:5px solid #900;} thead{} thead th{padding:1em 1em .5em;border-bottom:1px dotted #FFF;font-size:120%;text-align:left;} thead tr{} td{padding:.5em 1em;} tbody tr.odd td{background:transparent url(tr_bg.png) repeat top left;} tfoot{} tfoot td{padding-bottom:1.5em;} tfoot tr{} * html tr.odd td{background:#C00;filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='tr_bg.png', sizingMethod='scale');} #middle{background-color:#900;} </style> <body BGCOLOR=""#333333""> <table border=""1"" cellpadding=""5""> <table> <tbody> </tbody> </table> </body>" | Out-File $filename
Write-Host " Complete" -ForegroundColor Green
Write-Host "Your snapshot report has been saved to:" $filename
# Create mail message
$server = "yourmailserveraddress.com"
$port = 25
$to = "youremailaddress"
$from = "youremailaddress"
$subject = "vCenter Snapshot Report"
$message = New-Object system.net.mail.MailMessage $from, $to, $subject, $body
#Create SMTP client
$client = New-Object system.Net.Mail.SmtpClient $server, $port
# Credentials are necessary if the server requires the client # to authenticate before it will send e-mail on the client's behalf.
$client.Credentials = [system.Net.CredentialCache]::DefaultNetworkCredentials
# Try to send the message
try {
# Convert body to HTML
$message.IsBodyHTML = $true
$attachment = new-object Net.Mail.Attachment($filename)
$message.attachments.add($attachment)
# Send message
$client.Send($message)
"Message sent successfully"
}
# Catch an error
catch {
"Exception caught in CreateTestMessage1(): "
}
Another point worth mentioning – you should change the path that the report is saved to on disk – in my script it is set to F:\, so just modify this to suit your environment. Kudos to Andrew at winception for his Snapshot checking code – I have used a lot of it above, but modified it somewhat to include additional information, and style the HTML table so that it is much easier on the eyes. I also added the e-mail functionality to the script. The following is a screenshot after I executed the script in PowerCLI manually. You would of course look to automate the process by scheduling this script in on your machine.
Enjoy, and please drop any comments, improvements or feedback in the comments section!
