Backing Up SQL Database to Network Drive - Operating system error 5(Access is denied)

I ran into this issue the other day while trying to run a backup and store it on a network drive. At first, I thought it was a file permissions issue so I checked in the Security Settings and Audit logs, but no matter what permissions I changed, it still did not work.

The issue ended up being that the account that the SQL Server service runs under needs to be a Domain account and have the proper permissions. There was also a few other configuration issues I stumbled across.

1. Local Security Policy: Under the Local Security Policy(or Group Policy), there is a policy called "Lock pages in memory" and this needs to be enabled for the domain service account that will be used for the SQL Server service (I also changed the SQL Agent service).

2. The next steps were to allow us to reconfigure SQL Server and allow the SQL Agent to run as domain account:

sp_configure 'show advanced options', 1;

RECONFIGURE;

sp_configure 'awe enabled', 1

RECONFIGURE;

sp_configure 'show advanced options', 1;

RECONFIGURE;

sp_configure 'Agent XPs', 1;

RECONFIGURE

sp_configure 'show advanced options', 0;

RECONFIGURE

3. Change your SQL Server Service and SQL Agent service Logon account to a domain account with privileges on the network drive.
Open Services -> Choose the Service -> Logon tab -> Choose "This Account" and enter DOMAIN\ACCT and enter the password.