topic Re: Excess memory consumption from VM Host. in Operating System - HP-UX

Excess memory consumption from VM Host.

r4mp4g3 — Wed, 25 Nov 2009 12:19:41 GMT

Hi, I've installed a VM 4.10 Host over a blade 870c with 24 GB of physical memory.

I want to create two guests, with 14 and 6 GB, respectively.

According to HP official doc about VM requirements, the memory needed by the VM Host would be the following:

750MB + 7.5% de (24 - 1) = 2.470 GB

Besides, due to the 7% memory overhead needed by each VM guest, memory assignation would be this for both guests:

Guest A --> 14GB --> 107% of 14 = 14.98
Guest B --> 6GB --> 107% de 6 = 6.42

In theory, according to the calculations I've made before, if we've got an VM Host with 24GB of physical memory, the aggregate memory consumption if I wanna create two guests with 14 and 6 GB will be --> 2.470+ 14.98 + 6.42 = 23.870

The problem is that I create the first guest with 14GB but when I proceed to create the second one, it says I can only give 4730 megabytes to it. Why????

Re: Excess memory consumption from VM Host.

Torsten. — Wed, 25 Nov 2009 12:23:49 GMT

Try

# hpvmstatus -s

to show what is left.

Re: Excess memory consumption from VM Host.

Torsten. — Wed, 25 Nov 2009 12:28:54 GMT

The formula has changed a bit - consult the current manual for your version!

Re: Excess memory consumption from VM Host.

Torsten. — Wed, 25 Nov 2009 12:30:26 GMT

I hope it is readable:

Sufficient physical memory (RAM), including the following:
- 1250 MB + 8.5% of total memory.
- Total aggregate memory required for each guest (operating system and application
requirements)
HP-UX 11i v2May 2005 requires a minimum of 1 GB of memory, so a guest running
HP-UX must be configured with at least that much memory.
- Additional 8% of aggregate guestmemory for overhead for guests less than or equal
to 4 GB and between 8% and 8.3% for guests larger than 4 GB.
For example, for a VMHost with 16 GB of memory and two VMs configured with 3 GB
of memory each, the memory requirements would be calculated as follows:
- 2.58 GB for the VM Host (1250 MB plus 8.5% of 16 GB)
- 6.48 GB total guest requirement (108% of 6 GB)
- Total requirements = 9.06 GB of memory
This leaves 6.93 GB of memory for additional guests

Re: Excess memory consumption from VM Host.

r4mp4g3 — Wed, 25 Nov 2009 12:43:20 GMT

Ok! I didnt know that the formula had changed.

Nevertheless, about the "available memory" field shown when you perform a "hpvmstatus -s"... Is it possible that you assign ALL the memory left and that filed be zero or always have to be some amount of memory available there?

Re: Excess memory consumption from VM Host.

Torsten. — Wed, 25 Nov 2009 13:48:22 GMT

I don't think you can get close to zero.
If I perform the command I see 130MB free, some minutes later 120MB free and so on.

But I don't care about these small amount of memory.

Re: Excess memory consumption from VM Host.

r4mp4g3 — Wed, 25 Nov 2009 14:16:32 GMT

Ok, i see. Thanks so much, Torsten.