Memory Monitoring with Perfmon

Memory Object: Pages/Sec

What it monitors: Pages per second taken from RAM to Disk, higher the number the more I/O and possible performance issues for SQL .

What you want to see: Avg of 0-20, spikes should be things like backups, restores


Memory Object: Available Bytes

What it monitors: How much memory Is available
What you want to see: Anything greater than 5mb. With default configuration of SQL Memory settings. SQL “should” leave 4-10 mb of memory for the OS. If we see less than 5 then something in SQL is coursing problems


SQL Server: Memory Manager: Total Server Memory
SQL Server: Memory Manager: Target Server Memory

What it monitors: Total Server Memory covers how much memory is currently being used by SQL Server buffer pool. Target Server Memory is how much it would like to use.

What you want to see: If Target Server Memory is higher than Total then we need to upgrade memory


SQL Server Buffer Mgr: Lazy Writes/Sec

What it Monitors: Tracks how many times a second the LazyWriter process moves dirty pages from the buffer to disk in order to free up buffer space.

What you want to see: Should be close to zero. If it is exactly zero, this indicates that SQL Server's buffer cache is sufficiently large and SQL Server does not have to free up dirty pages, and will instead check the status at regular intervals. If the counter value is high more memory is required


Buffer Manager\Page Life Expectancy

What it Monitors: Amount of time in seconds that SQL expects a page to stay in the bufferpool.

What you want to see: MS recommends 300 PLE but large systems can be a lot higher