Not too well documented, but if you have the following scenario, you probably need to specify a UNC path to your backup destination instead of a local drive (i.e. use \servershare, instead of d:some_backup_folder).
- You have MOSS 2007 (or WSS 3.0)
- You are doing a backup via the GUI or using STSADM
- SQL Server is on a different server (i.e. you have a farm and not the standalone install)
- You are getting lots of errors about backing up content databases
You’ll need to sort out which accounts are trying to backup to the path, but you’ll need to a UNC. So there, now you know. I look forward to someone blogging this better than me ๐ or providing a Microsoft KB that outlines this better.