I was at a client location the other day and there was a need to configure PowerShell to back-up the SharePoint 2010 Farm after getting my commands ready and executing them it boomed out on me with the following errors
 
Verbose: [Database_Name] SQL command timeout is set to 1.00 hours.
Warning: [Database_Name] Cannot open backup device 'e:\etekglobalinc\backups\spbr0000\00000063.bak'. Operating system error 3(The system cannot find the path specified.).
 
The path seemed right but the .bak file didn’t exist which was the reason of the failure. After digging around I got the hook of things and I hope it saves someone a headache and some digging.
 
Reason for failure was because when PowerShell command for back-ups is executed, it backs everything in your farm including the databases thus if you have your databases on a different server the SQL Server Service Account needs to have access to the share where you backup files are being stored. So to resolve this error assign permission for the SQL Server Service Account to the file share and it should get rid of the error and allow farm to be backed up successfully.