Get-AzToolsStorageUsage.ps1

function Get-AzToolsStorageUsage {
    <#
    .SYNOPSIS
        Get Azure Storage Account summary information
    .DESCRIPTION
        Get Azure Storage Account container size and space used
    .PARAMETER Name
        Optional. Name of Storage Account
    .PARAMETER SelectContext
        Optional. Prompt to select the Azure context (tenant/subscription)
    .PARAMETER Scope
        Optional. Limit search to either Current Subscription or All Subscription (within the tenant)
        Default = CurrentSubscription
    .EXAMPLE
        Get-AzToolsStorageUsage -Scope AllSubscriptions
    .EXAMPLE
        Get-AzToolsStorageUsage -Name "sa123456xyz"
    .NOTES
    #>

    [CmdletBinding()]
    param (
        [parameter()][string]$Name = "",
        [parameter()][switch]$SelectContext,
        [parameter()][string][ValidateSet('CurrentSubscription','AllSubscriptions')]$Scope = 'CurrentSubscription'
    )
    if ($SelectContext) {
        Switch-AzToolsContext
    }
    try {
        $accounts = @()
        $context = Get-AzContext
        foreach ($azsub in (Get-AzSubscription -WarningAction SilentlyContinue)) {
            Write-Host "Checking subscription: $($azsub.Id) - $($azsub.Name)"
            try {
                $null = Set-AzContext $azsub
                $accounts += Get-AzStorageAccount
            } catch {
                Write-Warning "Subscription error: $($_.Exception.Message -join ';')"
            }
        }
        if (![string]::IsNullOrWhiteSpace($Name)) {
            $accounts = @($accounts | Where-Object {$_.StorageAccountName -eq $Name})
        }
        foreach ($account in $accounts) {
            $id  = $account.Id
            $sub = $($id -split '/')[2]
            try {
                $stMetric = Get-AzMetric -ResourceId $id -MetricName 'UsedCapacity' -ErrorAction Stop -WarningAction SilentlyContinue
                $usedCap  = $stMetric.Data
                $usedMB   = [math]::Round($usedCap.Average / 1MB, 2)
                $statmsg  = "success"
            } catch {
                $usedMB   = $null
                $statmsg  = "accessdenied"
            }
            [pscustomobject]@{
                StorageAccountName = $account.StorageAccountName
                StorageAccountId   = $id
                StorageSKU         = $account.Sku.Name
                ResourceGroup      = $account.ResourceGroupName
                Subscription       = $sub
                UsedSpaceMB        = $usedMB
                Message            = $statmsg
            }
        }
    } catch {
        Write-Warning "Error: $($_.Exception.Message)"
    } finally {
        $null = Set-AzContext $context
    }
}