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I'm running VMware Server 2.0.2 on my dual core Athlon server with 4 GB RAM and a RAID1 with two 400 GB SATA hard disks. This server's running three VMs at a time.

The host system is a Debian 5 x64 with the latest kernel and all updates installed. Besides VMware Server it doesn't run anything else.

The VMs do use non-fixed hard disk images. I'm running two VMs with 768 MB of RAM each, the third one uses 1.5 GB of RAM, so there should be another GB of free RAM for the host system.

Two VMs have a Ubuntu 9.10 x64 installed, the other one uses Debian 5 x64.

My problem is the very poor performance. In one of the VMs I'm running Apache with mod_rails (Phusion Passenger). None of the VMs do have to handle very heavy load. So after a time of idle the Passenger goes to sleep. Waking it up again takes up to 45 (!) seconds during which the VM doesn't really respond anymore due to the load generated while waking it up again. The load meter in the VM peaks up to a 10.00, which, in my opinion, can't be normal. On a (non-virtualized) test system I can't see such a behavior, so it has to be the VMware Server, doesn't it?

Sometimes even a simple SSH connect to one of the VMs generates a very high load, up to 8.00.

Someone told me that it is possible to direct a precise amount of CPU power and other resources to the VMs but I really don't know what to look for. Unfortunately Google didn't tell my either.

Any help is appreciated.

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This probably isn't what you want to hear but...

Forget about VMware Server and install ESXi. It's free, and you'll be guaranteed to experience much greater performance over VMware Server.

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OK, thanks for your help. I will go into this and give ESXi a try. But where can I find the free version of ESXi? Just registered at VMware and got a 60-day-trial. – Ulf Klose Feb 28 '10 at 22:03
Did you request a license key? Also, make sure you installed ESXi, not ESX. I believe ESXi will run for a couple months without a key, so you'll need to get that eventually. You can get a key for free from the VMware website: – EEAA Feb 28 '10 at 22:26
My fault, I clicked on ESX ;-). Thanks for your hint, I will give it a try. – Ulf Klose Mar 4 '10 at 0:54

One (of many) essential optimisation steps for VMWare is: Avoid using non fixed disks!

If you have a guest which often writes (and I think Apache will write constantly small ammounts for caching, logs and so on) VMWare needs to constantly increase disk size. If you got this three times in parallel, and use SATA disks - which are not really optimised for heavy parallel read/write operations - it'll bring your system very easy to ultra slow motion. It may also happen, that guest processes swap out their RAM when going to sleep, which also means a lot writes - and again host disk increasing...

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Thanks for your help, but this wouldn't explain the problems I have. My problem isn't a general lack of performance, moreover it seems like the VMs have to wake up again after a certain period of time which in my opinion is not necessary as I didn't delegate resources I don't have. – Ulf Klose Feb 28 '10 at 22:06

you should install the vmware-guest-addons to your virtual-host: on my setups that step increased performance.

it is always a good idea to have one VM on one cpu-core and one core left for the system:

eg: you have a quad core you can handle 3 very perfomant hosts on it

the problem depend on the chip: with 3 vms and the host on one dual-core chip, all the vms "fight" about the cpu-ressources - and in addition to it the process-scheduler needs a lot of cpu-time for himself.

modern chips have some sort of multithreading on each core, so this problem is not that hard

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Tried that but unfortunately the extensions do not build. Already googled around a lot but couldn't find a solution so far. I'm getting "funny" errors like In file included from /tmp/vmware-config9/vmhgfs-only/request.h:35, from /tmp/vmware-config9/vmhgfs-only/bdhandler.c:50: /tmp/vmware-config9/vmhgfs-only/compat_wait.h:78: error: conflicting types for ‘poll_initwait’ include/linux/poll.h:70: note: previous declaration of ‘poll_initwait’ was here when trying to build. – Ulf Klose Mar 4 '10 at 0:55

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