Does anyone have hands-on experience to share with regards to software raid performance under XenServer 5.5?
I've recently moved from VMware Server 1.x on Ubuntu to XenServer 5.5 hoping for an increase in performance by utilizing paravirtualization technology. Unfortunately I'm seeing very low performance on my md type software raid.
While the XenServer host is seeing numbers above 100 MB/s the paravirtualized guests are unable to get much more than 20 MB/s.
Is this to be expected, or should I look for a problem in my configuration?
I realize that software raid isn't ideal on a virtualization host, but for a home lab I can't justify a true hardware raid controller, while I still want some level of storage redundancy.
The host is not showing high cpu usage, system load or even excessive I/O wait cycles. This combined with the fact that VMware Server 1.x gave at least twice the I/O performance suggests that there must be some issue with the paravirtualization. Possibly due to lack of certain functionality in my hardware.
Since the full hardware virtualization of XenServer isn't all that great, I guess I'll be going back to VMware Server on Ubuntu, giving me a chance to try out the new 2.x version.