Total Physical Memory on the server is 25GB. SQL Server 'MAX MEMORY' is set to 20GB.

The SQL Server has been hanging. When this happens quite a large number of processes have lastwaittype displayed as 'RESOURCE_SEMAPHORE'. 'User Connections' is much, much higher than normal at the time the server hangs.

Does this mean that the processes are waiting for memory, and since there isn't sufficient memory and also since a large number of processes are waiting on memory, the server then just hangs?

Thank you.