I've been having some issues with backing up my primary configuration manager site. Configuration Manager 2012 was giving me the following critical error message:

 

Site backup task failure alert at site: P01

 

I am using a network (UNC) path which is related to why it's not working. To troubleshoot this issue, take a look at *:\Microsoft Configuration Manager\Logs\smsbkup.log.

 

First of all the network share need to have Everyone Full Control configured. The NTFS right needs to match the running account for the SMS_SITE_BACKUP and SMS_SITE_VSS_WRITER services.

 

You can configure a scheduled task for the backup at Administration - Site Configuration - Sites - Site Maintenance - Backup Site Server.

 

If you manually want to start a backup, run the service called SMS_SITE_BACKUP.

 

So to conclude. After changing the Log On account for the above mentioned services everything is working fine.

 

Cheers!