Using Powershell to Set Up SQL Server Mirroring

Management recently decided to use database mirroring as our DR solution. Because mirroring is done at the database level and not at the server level, I had a lot, a very lot of databases to be mirrored. To make it easier I decided to cobble together a simplistic script to do this.

I typically use a ‘management’ server for most of my needs and have therefore written the script to use UNC type pathing for the primary as well as mirror server. You will also notice I defaulted several of the parameters. This is handy when working on a set of servers for multiple databases.

<#
     .SYNOPSIS
          Set up a mirrored database
     .DESCRIPTION
          Backs up a database and tlog, copies it to the destination,
		  Restores the database on the mirror server, sets up the partner,
		  and starts the mirror.
     .PARAMETER  database
          The name of the database to be mirrored
     .PARAMETER  SourceServer
          The name of the primary server
     .PARAMETER  SourcePath
          Local Path for the backup
     .PARAMETER  DestServer
          The name of mirror server
     .PARAMETER  DestPath
          Local path for restore file
     .EXAMPLE
          PS C:\> Invoke-Mirror -database 'string value' 1
		  			-SourceServer 'string\string' -SourcePath 'string' `
					-DestServer 'string\string' -DestPath 'string'
     .NOTES
          AUTHOR:    John P. Wood
          CREATED:   July, 2010
          VERSION:   1.0.5
          The SQL connections rely on Windows authentication and assumes Endpoints
          already exist. Error checking is minimal (i.e. no check is made to
          verify the recovery model is FULL).
#>
Param(
	[Parameter(Mandatory=$true)]
	[string]$database,
	[string]$SourceServer='lcfsqlvs3\sqlvs3',
	[string]$SourcePath='U:\SQL Backups',
	[string]$DestServer='ldrsqlvs3\sqlvs3',
	[string]$DestPath='U:\SQL Backups'
	)
Set-StrictMode -Version 2
[Void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo")
[Void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO")
[Void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoExtended")
Function Get-FileName {
	Param([string]$path)
	$names = $path.Split('\\')
	$names[$names.Count - 1]
}
Function New-SMOconnection {
    Param (
		[string]$server
	)
	$conn = New-Object Microsoft.SqlServer.Management.Common.ServerConnection($server)
	$conn.applicationName = "PowerShell SMO"
	$conn.StatementTimeout = 0
	$conn.Connect()
	if ($conn.IsOpen -eq $false) {
		Throw "Could not connect to server $($server) for database backup of $($dbname)."
	}
	$smo = New-Object Microsoft.SqlServer.Management.Smo.Server($conn)
	$smo
}
Function Invoke-SqlBackup {
	$dbbk = new-object ('Microsoft.SqlServer.Management.Smo.Backup')
	$dbbk.Action = [Microsoft.SqlServer.Management.Smo.BackupActionType]::Database
	$dbbk.BackupSetDescription = "Full backup of " + $database
	$dbbk.BackupSetName = $database + " Backup"
	$dbbk.Database = $database
	$dbbk.MediaDescription = "Disk"
	$device = "$SourcePath\$bkpfile"
	$dbbk.Devices.AddDevice($device, 'File')
	$smo = New-SMOconnection -server $SourceServer
	Try {
		$dbbk.SqlBackup($smo)
		$dbbk.Action = [Microsoft.SqlServer.Management.Smo.BackupActionType]::Log
		$dbbk.SqlBackup($smo)
		$smo.ConnectionContext.Disconnect()
	}
	Catch {
		$ex = $_.Exception
		Write-Output $ex.message
		$ex = $ex.InnerException
		while ($ex.InnerException)
		{
			Write-Output $ex.InnerException.message
			$ex = $ex.InnerException
		};
		continue
	}
	Finally {
		if ($smo.ConnectionContext.IsOpen -eq $true) {
			$smo.ConnectionContext.Disconnect()
		}
	}
}
Function Invoke-SqlRestore {
	Param(
		[string]$filename
	)
	# Get a new connection to the server
    $smo = New-SMOconnection -server $DestServer
    $backupDevice = New-Object("Microsoft.SqlServer.Management.Smo.BackupDeviceItem") ($filename, "File")
	# Get local paths to the Database and Log file locations
	If ($smo.Settings.DefaultFile.Length -eq 0) {$DBPath = $smo.Information.MasterDBPath }
	Else { $DBPath = $smo.Settings.DefaultFile}
	If ($smo.Settings.DefaultLog.Length -eq 0 ) {$DBLogPath = $smo.Information.MasterDBLogPath }
	Else { $DBLogPath = $smo.Settings.DefaultLog}

	# Load up the Restore object settings
	$Restore = new-object Microsoft.SqlServer.Management.Smo.Restore
	$Restore.Action = 'Database'
	$Restore.Database = $database
    $Restore.ReplaceDatabase = $true
    $Restore.NoRecovery = $true
	$Restore.Devices.Add($backupDevice)

	# Get information from the backup file
	$RestoreDetails = $Restore.ReadBackupHeader($smo)
	$DataFiles = $Restore.ReadFileList($smo)

	# Restore all backup files
	ForEach ($DataRow in $DataFiles) {
        $LogicalName = $DataRow.LogicalName
        $PhysicalName = Get-FileName -path $DataRow.PhysicalName
		$RestoreData = New-Object("Microsoft.SqlServer.Management.Smo.RelocateFile")
		$RestoreData.LogicalFileName = $LogicalName
		if ($DataRow.Type -eq "D") {
			# Restore Data file
			$RestoreData.PhysicalFileName = $DBPath + "\" + $PhysicalName
		}
		Else {
			# Restore Log file
			$RestoreData.PhysicalFileName = $DBLogPath + "\" + $PhysicalName
		}
		[Void]$Restore.RelocateFiles.Add($RestoreData)

	}
	Try {
	$Restore.SqlRestore($smo)
	# If there are two files, assume the next is a Log
	if ($RestoreDetails.Rows.Count -gt 1) {
		$Restore.Action = [Microsoft.SqlServer.Management.Smo.RestoreActionType]::Log
		$Restore.FileNumber = 2
		$Restore.SqlRestore($smo)
	}
		$smo.ConnectionContext.Disconnect()
	}
	Catch {
		$ex = $_.Exception
		Write-Output $ex.message
		$ex = $ex.InnerException
		while ($ex.InnerException)
		{
			Write-Output $ex.InnerException.message
			$ex = $ex.InnerException
		};
		continue
	}
	Finally {
		if ($smo.ConnectionContext.IsOpen -eq $true) {
			$smo.ConnectionContext.Disconnect()
		}
	}
}
Function Set-Mirror {
	Param([string]$server,[string]$database,[string]$partner)
	$conn = "Server=$server; Integrated Security=SSPI; Database=Master"
	$cn = New-Object "System.Data.SqlClient.SqlConnection" $conn
	$cn.Open()
	$cmd = New-Object "System.Data.SqlClient.SqlCommand"
	$cmd.CommandType = [System.Data.CommandType]::Text

	$cmd.CommandText = "ALTER DATABASE $database SET PARTNER = 'TCP://" + $partner + ":5022'"
	$cmd.Connection = $cn
	$cmd.ExecuteNonQuery()
	$cn.Close()
	Trap {
		$ex = $_.Exception
		Write-Output $ex.message
		$ex = $ex.InnerException
		while ($ex.InnerException)
		{
			Write-Output $ex.InnerException.message
			$ex = $ex.InnerException
		};
		continue
	}
}
$srcUNC = Join-Path "\\$($SourceServer.Split('\\')[0])" $($SourcePath.Replace(':','$'))
if (-not(Test-Path $srcUNC)) { New-Item $srcUNC -ItemType directory | Out-Null}
$destUNC = Join-Path "\\$($DestServer.Split('\\')[0])" $($DestPath.Replace(':','$'))
if (-not(Test-Path $destUNC)) { New-Item $destUNC -ItemType directory | Out-Null}
$bkpfile = $($SourceServer.Replace("\", "$")) + "_" + $database + "_FULL_" + $(get-date -format yyyyMMdd-HHmmss) + ".bak"
Invoke-SqlBackup
Copy-Item $(Join-Path $srcUNC $bkpfile) -Destination $destUNC -Verbose
Invoke-SqlRestore -filename $bkpfile
# Establish Mirroring from the mirrored database
Set-Mirror -server $DestServer -database $database -partner $($SourceServer.Split('\\')[0])
# Start the mirror
Set-Mirror -server $SourceServer -database $database -partner $($DestServer.Split('\\')[0])

6 thoughts on “Using Powershell to Set Up SQL Server Mirroring

  1. Vanzerhous

    John, this script is fantastic!
    I really appreciate you taking the time to post; it’s very helpful!
    Any chance you could include some status routines for backup, restore and copy progress?
    Thanks Dude!

  2. John Wood Post author

    Because most of my scripts run unattended, there is no current plan to add progress indicators. This may change in the future. My biggest problem, at this point, is presenting good error information for a script which implodes while running as a Windows task or an SQL Server job.

  3. Vanzerhous

    Gotch, I added progress indicator for the file copy portion of your script since lots of my DB BAK files (compressed) are typically over 100GB. Anyway, your script has worked flawlessly for me! Thanks again!

  4. Pingback: Mise en place du database mirroring sur SQL Server avec PowerShell | ODIN | Osiatis Développement et Ingénierie Normandie

  5. ido.kaplan

    Hi,

    I’m getting this exception on SQL 2016.

    Failed to connect to server Data Source=X.dom\MSSQLSERVER,1433;Integrated Security=True;MultipleActiveResultSets=False;Encrypt=False;TrustServerCertificate=False;Application Name=”PowerShell SMO”.
    The value’s length for key ‘data source’ exceeds it’s limit of ‘128’.

    Can you please advise?
    Thanks!
    Ido

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