Maintaining acceptable performance in a virtualized environment is a key initiative. Unfortunately, it can be somewhat difficult to troubleshoot the hypervisor layer when it comes to disk I/O and Network I/O. If you are running Citrix XenServer as your hypervisor layer, then you are in luck. Citrix has released a new tool (well, actually a virtual appliance of sorts) call PerformanceVM. PerformanceVM is a XenServer virtual machine that helps troubleshoot performance related issues, such as poor performance caused by storage I/O and network I/O. The virtual machine, built on Debian Linux, equips with following test utilities and is accessible using a Web based user interface:
Disk I/O performance utility - It can be used to conduct the following disk I/O operations to measure: sequential read/writes and random read/writes with various specified block sizes. This performance testing utility assesses the performance of a given Storage Repository by reading and writing data to a test virtual disk, created by the user specifically for this test.
Network I/O performance utility - It is essentially a modified version of Netperf. Additional information about Netperf can be found at http://www.netperf.org. Netperf runs on the backend and provides end-to-end request/response round trip latency and TCP/UDP throughput tests.