VMware Cloud Community
Dave1577
Contributor
Contributor

High memory utilization

I am trying to figure out what to make of a Windows 2008 server utilizing 100% of it memory according to Task Manager inside the guest, but showing 40% used when looking at it from the performance tab outside the guest. There is no ballooning or swapping. Does this indicate the need to add more memory to the guest? It is a SQL server.

Thanks 

0 Kudos
5 Replies
Troy_Clavell
Immortal
Immortal

Hello and Welcome to the Forums!

It is a SQL server.

SQL will reserve all memory it can.  My guess it SQL is "using" the memory.  You may have to throttle SQL a bit

http://support.microsoft.com/kb/321363

0 Kudos
Dave1577
Contributor
Contributor

SQL server is definately using most of the memory. Thank you for the article. Should I see a correlation between the 2 values above?

0 Kudos
Troy_Clavell
Immortal
Immortal

I would go by the performance charts within the guest OS, they are going to be the most accurate.

0 Kudos
farri304
Contributor
Contributor

Hey Troy,

Im seeing the exact same thing w my 2008 R2 SQL VM. Task Manager and Resource Monitor are showing the memory utilization at 98% while active (from vCenter Performance Charts, ESXTOP, and Perf Mon) is around 1Gb. I don't typically see this in non SQL VMs. Im trying to understand why active(in the vCenter charts) isn't reflecting these numbers. Since SQL is using this memory in its buffer pool(allocating and freeing memory depending on the other applications' needs, shouldn't the hypervisor see that memory as "active"? Those pages are being allocated and freed by the OS and since the hypervisor has no insight into the VMs virtual memory I would assume that it thinks the VM is actively using all those pages.

The only reason(guessing here) is that those pages have become idle overtime. And while the SQL buffer pool is allocating and freeing those pages its only doing it at the low end(1Gb aka active) memory. The rest isnt needed and has become idle according to the hypervisor even though within the Guest OS(perfmon, taskmgr) it sees it as in use, and at 98%.

Is this correct? Close? Way off? Completely wrong and need to just go away? Smiley Happy 

Thanks

Joe

Twitter: @joefarri
0 Kudos
admin
Immortal
Immortal

Hi Dave1577

Welcome to the communites

Before suggesting any thing else First we need to know what role that

Server performing and existing hardware configuration.

ther are many more possibbilites like virus, application not responding or

compatibility problem etc.

"Life is never easy for those who dream"
0 Kudos