Vmware Maximum Host Memory

[hennessy1]

I have 24GB of ram installed but vmware workstation 8 is only allowing 18GB to be used by a vm. Is that right or is there somthing wrong it seems like that is alot of memory for it to not be available to vmware?

 

[yinan]

i think it also guesses due to memory that the OS is using.

 

[hennessy1]

Well I've added a large amount more ram and now it seems to be reserving 15GB of ram just for the OS which is alot of memory to not be using. Anyone know how I can change that or if I even can?

 

[mzkhadir]

http://kb.vmware.com/selfservice/mi...nguage=en_US&cmd=displayKC&externalId=1014006

if you paid for wks 8, why not call support or post in vmware forums

 

[imagoon]

Marking for my curiosity. I have successfully brought my machine to its knees with workstation...

 

[quikah]

http://communities.vmware.com/message/1831411

File a support request, this is by design, they are being too conservative. The only way they will change it is if enough people complain. There are some options you can try in the above thread.

There was a similar problem in ESX, a % of memory is reserved for the kernel (I think it was 6% in ESX 4). This was fine for most system, until you put in 256GB and found that you were losing 15+ GB of RAM. They changed it in 5.0 to not be a straight %, it now varies based on the total RAM in the system now.

 

[Emulex]

no way. i have boxes from 8gb to 80gb and esxi does not use anywhere near that. now that dual port 10gbe nic uses 2GB (1gb per port) and that video card eats 1GB - follow? but i swear esxi overhead is tiny.

maybe you are using windows 2008R2 with hyper-v that eats way more like a gig. lol

 

[quikah]

no way. i have boxes from 8gb to 80gb and esxi does not use anywhere near that. now that dual port 10gbe nic uses 2GB (1gb per port) and that video card eats 1GB - follow? but i swear esxi overhead is tiny.

It is not overhead. The kernel will keep 6% of the memory free by swapping or ballooning. I guess reserved is not really the right wording. See http://www.yellow-bricks.com/2011/03/17/minfreepct-6-or-should-it-be-less/

 

[hennessy1]

Well I have tried what "quickah" had posted from the vmware forums with no luck. I had also contacted VMware for support and their first suggestion was to delete the prefrences.ini file but that resulted in no luck either.

 

[hennessy1]

I have been in contact with VMware and this is their response to having vmware allocate more memory to guest machines.


"I understand your requirement and the situation that blocks you from allocating more memory to virtual machines inside vmware , but it is not a barrier since the virtual memory need an effective communication with the physical memory. It is not a software program or other technique that block you from allocating more memory and it is the memory management technique on the host OS.If we try to change it by developing a software or by other means it will leeds to a freezing issue on the machine.


The allocation to the virtual layer is in the control of the host os.Virtual memory is a method of decoupling the memory organisation from the actual physical hardware. The applications operate memory via virtual adresses. Each time an attempt to access the actual data is made, virtual memory subsystem translates the virtual address to a physical address, which corresponds to the address of the data as seen by the hardware. The address translation process itself is managed by the operating system. In this way addition of virtual memory enables granular control over the main memory and ways to access it. This can be used to increase the effectiveness of memory management.


If the memory on a host machine increased , the host will have to consume more memory for the better performance according to memory management process."