functions/Get-DbaDbSpace.ps1

function Get-DbaDbSpace {
<#
    .SYNOPSIS
        Returns database file space information for database files on a SQL instance.
         
    .DESCRIPTION
        This function returns database file space information for a SQL Instance or group of SQL Instances. Information is based on a query against sys.database_files and the FILEPROPERTY function to query and return information.
         
        File free space script borrowed and modified from Glenn Berry's DMV scripts (http://www.sqlskills.com/blogs/glenn/category/dmv-queries/)
         
    .PARAMETER SqlInstance
        Specifies the SQL Server instance(s) to scan.
         
    .PARAMETER SqlCredential
        Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
         
    .PARAMETER Database
        Specifies the database(s) to process. Options for this list are auto-populated from the server. If unspecified, all databases will be processed.
         
    .PARAMETER ExcludeDatabase
        Specifies the database(s) to exclude from processing. Options for this list are auto-populated from the server.
         
    .PARAMETER IncludeSystemDBs
        If this switch is enabled, system databases will be processed. By default, only user databases are processed.
         
    .PARAMETER EnableException
        By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
        This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
        Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
         
    .NOTES
        Tags: Database, Space, Storage
        Author: Michael Fal (@Mike_Fal), http://mikefal.net
         
        Website: https://dbatools.io
        Copyright: (c) 2018 by dbatools, licensed under MIT
        License: MIT https://opensource.org/licenses/MIT
         
    .LINK
        https://dbatools.io/Get-DbaDbSpace
         
    .EXAMPLE
        PS C:\> Get-DbaDbSpace -SqlInstance localhost
         
        Returns all user database files and free space information for the localhost.
         
    .EXAMPLE
        PS C:\> Get-DbaDbSpace -SqlInstance localhost | Where-Object {$_.PercentUsed -gt 80}
         
        Returns all user database files and free space information for the local host. Filters the output object by any files that have a percent used of greater than 80%.
         
    .EXAMPLE
        PS C:\> 'localhost','localhost\namedinstance' | Get-DbaDbSpace
         
        Returns all user database files and free space information for the localhost and localhost\namedinstance SQL Server instances. Processes data via the pipeline.
         
    .EXAMPLE
        PS C:\> Get-DbaDbSpace -SqlInstance localhost -Database db1, db2
         
        Returns database files and free space information for the db1 and db2 on localhost.
         
#>

    [CmdletBinding()]
    param ([parameter(ValueFromPipeline, Mandatory)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [System.Management.Automation.PSCredential]$SqlCredential,
        [Alias("Databases")]
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [switch]$IncludeSystemDBs,
        [Alias('Silent')]
        [switch]$EnableException
    )

    begin {
        Write-Message -Level System -Message "Bound parameters: $($PSBoundParameters.Keys -join ", ")."

        $sql = "SELECT SERVERPROPERTY('MachineName') AS ComputerName,
                                   ISNULL(SERVERPROPERTY('InstanceName'), 'MSSQLSERVER') AS InstanceName,
                                   SERVERPROPERTY('ServerName') AS SqlInstance,
                    DB_NAME() as DBName
                    ,f.name AS [FileName]
                    ,fg.name AS [Filegroup]
                    ,f.physical_name AS [PhysicalName]
                    ,f.type_desc AS [FileType]
                    ,CAST(CAST(FILEPROPERTY(f.name, 'SpaceUsed') AS int)/128.0 AS FLOAT) as [UsedSpaceMB]
                    ,CAST(f.size/128.0 - CAST(FILEPROPERTY(f.name, 'SpaceUsed') AS int)/128.0 AS FLOAT) AS [FreeSpaceMB]
                    ,CAST((f.size/128.0) AS FLOAT) AS [FileSizeMB]
                    ,CAST((FILEPROPERTY(f.name, 'SpaceUsed')/(f.size/1.0)) * 100 as FLOAT) as [PercentUsed]
                    ,CAST((f.growth/128.0) AS FLOAT) AS [GrowthMB]
                    ,CASE is_percent_growth WHEN 1 THEN 'pct' WHEN 0 THEN 'MB' ELSE 'Unknown' END AS [GrowthType]
                    ,CASE f.max_size WHEN -1 THEN 2147483648. ELSE CAST((f.max_size/128.0) AS FLOAT) END AS [MaxSizeMB]
                    ,CAST((f.size/128.0) AS FLOAT) - CAST(CAST(FILEPROPERTY(f.name, 'SpaceUsed') AS int)/128.0 AS FLOAT) AS [SpaceBeforeAutoGrow]
                    ,CASE f.max_size WHEN (-1)
                                        THEN CAST(((2147483648.) - CAST(FILEPROPERTY(f.name, 'SpaceUsed') AS int))/128.0 AS FLOAT)
                                        ELSE CAST((f.max_size - CAST(FILEPROPERTY(f.name, 'SpaceUsed') AS int))/128.0 AS FLOAT)
                                        END AS [SpaceBeforeMax]
                    ,CASE f.growth WHEN 0 THEN 0.00
                                    ELSE CASE f.is_percent_growth WHEN 0
                                                    THEN CASE f.max_size
                                                            WHEN (-1)
                                                            THEN CAST(((((2147483648.)-f.Size)/f.Growth)*f.Growth)/128.0 AS FLOAT)
                                                            ELSE CAST((((f.max_size-f.Size)/f.Growth)*f.Growth)/128.0 AS FLOAT)
                                                            END
                                                    WHEN 1
                                                    THEN CASE f.max_size
                                                            WHEN (-1)
                                                            THEN CAST(CONVERT([int],f.Size*power((1)+CONVERT([float],f.Growth)/(100),CONVERT([int],log10(CONVERT([float],(2147483648.))/CONVERT([float],f.Size))/log10((1)+CONVERT([float],f.Growth)/(100)))))/128.0 AS FLOAT)
                                                            ELSE CAST(CONVERT([int],f.Size*power((1)+CONVERT([float],f.Growth)/(100),CONVERT([int],log10(CONVERT([float],f.Max_Size)/CONVERT([float],f.Size))/log10((1)+CONVERT([float],f.Growth)/(100)))))/128.0 AS FLOAT)
                                                            END
                                                    ELSE (0)
                                                    END
                                    END AS [PossibleAutoGrowthMB]
                    , CASE f.max_size WHEN -1 THEN 0
                                        ELSE CASE f.growth
                                                WHEN 0 THEN (f.max_size - f.size)/128
                                                ELSE CASE f.is_percent_growth
                                                        WHEN 0
                                                        THEN CAST((f.max_size - f.size - ( CONVERT(FLOAT,FLOOR((f.max_size-f.Size)/f.Growth)*f.Growth)))/128.0 AS FLOAT)
                                                        ELSE CAST((f.max_size - f.size - ( CONVERT([int],f.Size*power((1)+CONVERT([float],f.Growth)/(100),CONVERT([int],log10(CONVERT([float],f.Max_Size)/CONVERT([float],f.Size))/log10((1)+CONVERT([float],f.Growth)/(100)))))))/128.0 AS FLOAT)
                                                        END
                                                END
                                    END AS [UnusableSpaceMB]
 
                FROM sys.database_files AS f WITH (NOLOCK)
                LEFT OUTER JOIN sys.filegroups AS fg WITH (NOLOCK)
                ON f.data_space_id = fg.data_space_id"

    }

    process {
        foreach ($instance in $SqlInstance) {
            try {
                Write-Message -Level VeryVerbose -Message "Connecting to $instance." -Target $instance
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential
            }
            catch {
                Stop-Function -Message "Failed to process Instance $Instance." -ErrorRecord $_ -Target $instance -Continue
            }

            if ($server.VersionMajor -lt 9) {
                Write-Message -Level Warning -Message "SQL Server 2000 not supported. $server skipped."
                continue
            }

            #If IncludeSystemDBs is true, include systemdbs
            #look at all databases, online/offline/accessible/inaccessible and tell user if a db can't be queried.
            try {
                if (Test-Bound "Database") {
                    $dbs = $server.Databases | Where-Object Name -In $Database
                }
                elseif ($IncludeSystemDBs) {
                    $dbs = $server.Databases | Where-Object IsAccessible
                }
                else {
                    $dbs = $server.Databases | Where-Object { $_.IsAccessible -and $_.IsSystemObject -eq 0 }
                }

                if (Test-Bound "ExcludeDatabase") {
                    $dbs = $dbs | Where-Object Name -NotIn $ExcludeDatabase
                }
            }
            catch {
                Stop-Function -Message "Unable to gather databases for $instance." -ErrorRecord $_ -Continue
            }

            foreach ($db in $dbs) {
                try {
                    Write-Message -Level Verbose -Message "Querying $instance - $db."
                    If ($db.status -ne 'Normal' -or $db.IsAccessible -eq $false) {
                        Write-Message -Level Warning -Message "$db is not accessible." -Target $db
                        continue
                    }
                    #Execute query against individual database and add to output
                    foreach ($row in ($db.ExecuteWithResults($sql)).Tables.Rows) {
                        if ($row.UsedSpaceMB -is [System.DBNull]) {
                            $UsedMB = 0
                        }
                        else {
                            $UsedMB = [Math]::Round($row.UsedSpaceMB)
                        }
                        if ($row.FreeSpaceMB -is [System.DBNull]) {
                            $FreeMB = 0
                        }
                        else {
                            $FreeMB = [Math]::Round($row.FreeSpaceMB)
                        }
                        if ($row.PercentUsed -is [System.DBNull]) {
                            $PercentUsed = 0
                        }
                        else {
                            $PercentUsed = [Math]::Round($row.PercentUsed)
                        }
                        if ($row.SpaceBeforeMax -is [System.DBNull]) {
                            $SpaceUntilMax = 0
                        }
                        else {
                            $SpaceUntilMax = [Math]::Round($row.SpaceBeforeMax)
                        }
                        if ($row.UnusableSpaceMB -is [System.DBNull]) {
                            $UnusableSpace = 0
                        }
                        else {
                            $UnusableSpace = [Math]::Round($row.UnusableSpaceMB)
                        }

                        [pscustomobject]@{
                            ComputerName         = $server.ComputerName
                            InstanceName         = $server.ServiceName
                            SqlInstance          = $server.DomainInstanceName
                            Database             = $row.DBName
                            FileName             = $row.FileName
                            FileGroup            = $row.FileGroup
                            PhysicalName         = $row.PhysicalName
                            FileType             = $row.FileType
                            UsedSpaceMB          = $UsedMB
                            FreeSpaceMB          = $FreeMB
                            FileSizeMB           = $row.FileSizeMB
                            PercentUsed          = $PercentUsed
                            AutoGrowth           = $row.GrowthMB
                            AutoGrowType         = $row.GrowthType
                            SpaceUntilMaxSizeMB  = $SpaceUntilMax
                            AutoGrowthPossibleMB = $row.PossibleAutoGrowthMB
                            UnusableSpaceMB      = $UnusableSpace
                        }
                    }
                }
                catch {
                    Stop-Function -Message "Unable to query $instance - $db." -Target $db -ErrorRecord $_ -Continue
                }
            }
        }
    }
    end {
        Test-DbaDeprecation -DeprecatedOn "1.0.0" -Alias Get-DbaDatabaseFreeSpace
        Test-DbaDeprecation -DeprecatedOn "1.0.0" -Alias Get-DbaDatabaseSpace
    }
}