PowerShell to backup a Web application

Question

I need a PowerShell script which could perform the following:

• How to Back up and Content Database of a Web Application
• Restore a Content Database on a newly created Web Application

Answer 1

If both web apps are in the same farm, the fastest and easiest way is to detach DB from app A and reattach DB from B.

$srcApp = Get-SPWebApplication http://app1
$targetApp = Get-SPWebApplication http://app2

$dbs = Get-SPContentDatabase -WebApplication $srcApp  | % { $_.Name }

Get-SPContentDataBase -WebApplication $srcApp | Dismount-SPContentDataBase

Remove-SPWebApplication

$dbs | % { Mount-SPContentData -Name $_ -WebApplication $targetApp }

This script should do the job (can't test by now, don't fire it blindly).

[Edit] and of course, backup the whole content database before

Answer 2

Using the SharePoint PowerShell console

Backup-SPFarm -Directory <BackupFolder> -BackupMethod {Full | Differential} -Item <WebApplicationName> [-Verbose]

See this MSDN article: Use Windows PowerShell to back up a Web application in SharePoint Server.

Use this command to restore a content DB:

Restore-SPFarm -Directory <Backup folder name> -RestoreMethod Overwrite -Item <Content database name> [-BackupId <GUID>] [-Verbose]

See this TechNet article: Use Windows PowerShell to restore a SharePoint content database.

Please ensure that you understand these commands and run tests to know what is going to happen. Other links:

Restore-SPFarm

Backup-SPFarm

http://technet.microsoft.com/en-us/library/ee890117