Azure Tip: Use PowerShell to check all blob spaced used in a Storage Account

Just recently, I had the need to be able to know the exact volume of all blob container data, within a specific Azure Storage Account.

This was part of a migration project, which in this case meant that I needed to report that data amount multiple times per day. Data was constantly being copied to and deleted from that Storage account, and the same applies to Blob containers being created, filled with data and deleted afterwards. So my only constant was the Storage Account, and I needed to know, every 2 hours, what was the volume of blob container data in that account.

After a quick of research I found this outstanding Microsoft article on how to leverage the Azure PowerShell module (yes, PowerShell to save the day again!!) to calculate the size of a Blob Storage Container.

The only limitation with the script in the article above was that it’s calculating the size of a single blob container, and I needed the combined size of all blob containers in my Storage Account.

So I had to adapt that script to my scenario, and I turned it into the following script:

# Connect to Azure

# Static Values for Resource Group and Storage Account Names
$resourceGroup = "ChangeToYourResourceGroupName"
$storageAccountName = "changetoyourstorageaccountname"

# Get a reference to the storage account and the context
$storageAccount = Get-AzureRmStorageAccount `
-ResourceGroupName $resourceGroup `
-Name $storageAccountName
$ctx = $storageAccount.Context

# Get All Blob Containers
$AllContainers = Get-AzureStorageContainer -Context $ctx
$AllContainersCount = $AllContainers.Count
Write-Host "We found '$($AllContainersCount)' containers. Processing size for each one"

# Zero counters
$TotalLength = 0
$TotalContainers = 0

# Loop to go over each container and calculate size
Foreach ($Container in $AllContainers){
$TotalContainers = $TotalContainers + 1
Write-Host "Processing Container '$($TotalContainers)'/'$($AllContainersCount)'"
$listOfBLobs = Get-AzureStorageBlob -Container $Container.Name -Context $ctx

# zero out our total
$length = 0

# this loops through the list of blobs and retrieves the length for each blob and adds it to the total
$listOfBlobs | ForEach-Object {$length = $length + $_.Length}
$TotalLength = $TotalLength + $length
# end container loop

#Convert length to GB
$TotalLengthGB = $TotalLength /1024 /1024 /1024

# Result output
Write-Host "Total Length = " $TotallengthGB "GB"


The script above will provide you an output into the console of the total volume, in GB, that you have on a specific storage account.

To execute the script, follow the steps below:

  • Copy the entire code above to a notepad
  • Change the values of line 2 and 3, to the correct names of your Azure Resource group and your Azure Storage Account
  • Save the file as .ps1
  • Open a PowerShell window and execute the “script.ps1” file you just saved (see screenshot below)
  • Authenticate with your Azure username and password, when prompted


Execute the script as shown above.


When prompted, authenticate.


And this is how the end result should look like.

Before I end this blog post I’d just like to point out that this script was written in a very simplistic way, and to address an urgent need that I had. With a couple more hours of work, you can make this script even easier to use and add all sorts of different features to it, such as:

  • Error handling
  • remove the hard coded values and list for selection all available storage accounts and resource groups
  • change the output format (i.e to CSV) and list sizes per blob container
  • allow you to select between multiple Azure subscriptions under the same account

The above are just some ideas on how to improve the script. I haven’t done it because I had no need for it, but by all means please let me know if you want/need an improved version. This one works just fine, if all you want is the total volume of blob data in a specific storage account.

Happy New Year!!!


Azure Resource Manager PowerShell: How to change between subscriptions

Today’s post is a very simple one. For those of you that like me, have multiple subscriptions on your Azure account and automate a lot of your Azure work via PowerShell, you might need to change between subscriptions, in the same PowerShell session, to execute multiple tasks.

This can be done with one of the two following cmdlets:

And here is where the confusion comes. What’s the difference between the two cmdlets and which one should you use?

Well the answer is the cmdlets do the exact same thing, and you should use the “Set-AzureRMContext” cmdlet, specially if you put it into scripts, since it seems to be the replacement for the “Select-AzureRMSubscription” cmdlet.

In fact, this is what you get when you do a “Get-Help Select-AzureRMContext”:


As you can see above all references point to the new cmdlet.

Now a quick note on how the cmdlet works.

To list all of your subscriptions:


To change the context to a different subscription:

Set-AzureRMContext -subscription <SubscriptionID or SubscriptionName>

I hope the above is helpful. Happy scripting!