Guest Mem - % in virtual machine tab is meaningless?

[5oadmin]

Hi - so I have read about ballooning, shared, private and everthing about vmware RAM allocation.

However I'm still not getting the 'guest mem %' column in the virtual machine tab for any given cluster.

For example I have a machine which shows:

- in windows task manager, total physical : 4gb, avail : 1gb. Commit charge: 7gb

- in vmware 'resource allocation' tab: private : 3.9gb, balloon 0, unaccessed 5mb, shared 95mb. Consumed: 4gb.

BUT in the virtual machine tab for the host I see: host mem 4gb (ok) and guest mem %: 18%

IT doesn't make any sense as guest mem % is meant to represent the % of the GUEST memory use - which in this case should be 75% or 100% depending on how you look at it, but certainly not 18%.

[rolohm · Accepted solution]

As I have understood it the guest mem % is caculated using something called "active memory". Active memory is memory that has been actively used "resently" (I don't know what "resently" refers to in quantified time tho). What you see inside windows, in the task manager, is allocated memory from windows point of view, but windows is (acording to the guest mem parameter) only activly using 18% of 4GB i.e. 720MB. A nice information to have if you plan to make a memory reservation for that VM and you actually want to know what to set the reservation to since the rest of the memory could be balooned (swapped) out without any noticable decrease in performance of the VM.

/R

[5oadmin]

Cheers - makes sense. Too bad vmware doens't allow to read what the task manager says from a central location - would make allocating ram a lot easier.

[rolohm]

True that.

But in vSphere4 (ESX4) they've done it the other way around, so that you can see vmware performance parameters in a Windows VM's task manager. Will come in very handy, I think.

/R