VMware Server : Performance tweak tips

By | September 23, 2011

VMware Server performance can be improved in so many ways… there are some recomendation that I’ve discovered when I was using this product at large before moving them to ESXi :

  • Use preallocated virtual disk
  • Use as less virtual hardware as possible – do not add unneeded hardware
  • Use ext4 or XFS filesystem (if host run under Linux – be careful with XFS, does not react so well with power outage!)
  • Use fast enough hardware (depending on your usage – have as more ram you can afford and avoid host and guests to swap!)

Avoid unused memory to be reallocated to the host, this consume a lot of CPU power.  Since VMware Server 2, this option has been removed from the GUI. You need to add the following parameter in the virtual machine config file (.vmx)

Set the following filesystem attribute (edit /etc/fstab) to save on disk I/O (on host as well on guests) :


Use the following kernel parameters for linux guests (the first parameter is to solve the known time synchronization problem) :

Do NOT add a second virtual CPU if you are running VM on a single socket machine. Multiple core CPU does not count… enable this only if your motherboard have two physical CPU.

In such case, and you probably running a modern Linux distribution with a stock kernel, you should disable the SMP function… just add the following kernel parameter (/boot/grub/grub.conf) :