Monitoring free disk space on SQL Server servers becomes crucial if your database growth is relatively fast. If you don’t have direct access to your server’s hard disks, xp_fixeddrives provides an easy way to monitor free disk space remotely.
The xp_fixeddrives system stored procedure returns a list of physical hard drives and the amount of free space on each one.
xp_fixeddrives is an undocumented system stored procedure. Microsoft may not include it in future releases of SQL Server 2000 or MSDE.