To back up a single web application using the SharePoint 2010 Management Shell, execute the following command, as shown in Figure 10.17:
backup-spfarm –BackupMethod Full –Directory C:Backup -Item http://server
Figure 10.17. Backing up a web application using PowerShell.
http://server is the name of the web application to be backed up using the Full method. If the web application is being backed up for the first time, it has to be full backup, or else the backup will fail in case of first-time differential backup.
The advantage of using Windows PowerShell is in executing multiple instances of Windows PowerShell scripts to back up site collections using the BackUpThreads parameter in backup-spfarm. The recommended value for SharePoint Foundation is 3 threads.