We are experiencing performance issues with a VMware Server 2.x installation on an Ubuntu 8.04 host. When the host system is generating IO load (for example, copying large files as part of a backup operation), the guests (also Ubuntu 8.04) become extremely unresponsive and slow (simple Apache HTTP requests taking 5 seconds instead of the usual 200ms).
We tried optimizing various aspects of the VMs, but the issue remains. Is there a known bug with VMware performance under linux if host IO load is high? Is there a way to fix this? Is this only an issue with Ubuntu systems, or have you seen it on other systems before? Thanks!
Best Answer
Is there a reason you're running VMware Server instead of ESXi? ESXi is free, and will give you significantly better performance, both in terms of Disk/Network IO as well as CPU and memory performance as well.
What you're seeing is is pretty normal - you're getting high levels of IO contention on the host and everybody is being forced to wait their turn for the physical resources of the server. To fix this, consider moving to ESX, ESXi, or possibly using faster hard drives.