Physical memory is almost consumed

[Former Member]

Hello Experts,

Our system is on virtual machine. Sap version is ECC 6.0, Operating system is SUSE Linux and the database is DB6 release 10.01.0001.

And the physical memory is 24 GB and there are only 50 users.Now the problem is almost the physical memory is consumed by the processes only 300 MB physical memory is free now i have checked there is no long running background job.can you please help me to find out the reason and the solution how can i release the memory.

Thanks in advance for your support and time .

[MarioDeFelipe · Accepted solution]

Hello Tushar

Having only 300 Mb of free memory is not a problem by itself, the problem is if you see swaping.

Do you see swaping on the OS using "top" command, or do you see swaping on ST02 transaction, or any dump in st22 due to memory problems?

[Former Member · Accepted solution]

Hello Mr. Felipe,

Thanks for your reply !

No, issue is not there. I have checked no dumps are there because of memory swapping is also not there, even no performance issue from customer side. but I am little afraid I hope it will not create any problem. but the point is for 50  users 24 GB physical memory is enough as I think it should not consume this much of memory ?

[MarioDeFelipe · Accepted solution]

We should not extrapolate number of users vs quantity of memory consumed, one single user can collapse your system using a program inappropaitely (or a non-limited Z program that can consume all the memory by itself)

Memory consumption is something that needs to be monitored from time to time but should not be on top of our priority lists if we dont get dumps or users complain of performance issues. Its there to be consumed.

SAP normally takes the memory and you dont see that the memory is returned to the OS, but you should not be concerned of that as long as you dont get dumps or you don't see swapping.

24 Gb for a VM that includes the DB might be tight eventually, but you will see that in ST02 (if you are oversized or undersized), ST06 (if system is swapping) and ST03 (if you have a performance problem).

there is a very interesting SAP Press book called Performance Optimization Guide that explains a lot about all this.