Q: Slow I/O on VM hosts I am currently debugging guests of a host of mine that is suffering from high latency but acceptable read/write speeds on CentOS 6. This VM is connected to a VM host which has its storage on a SAN that I am reading/writing to. 7K/10K RPM HDDs.
Here is a test output (CentOS - LSI Logic SAS):
1073741824 bytes (1.1 GB) copied, 10.4863 s, 102 MB/s

Here is another test output (Windows - same SAN, different volume, VMWare Paravirtual, updated tools):
Read IO 9MiB/s, 1152 I/O per s, 582ms latency on last I/O request

Here is yet another test ouput from a machine with direct access to SAN:
Read IO 90MiB/s, 11575 I/O per s, 667ms latency on last I/O request

Am I facing a throttle or bottleneck through VMWare or are there a bigger issue? How do I go about solving this issue as I am getting acceptable speeds on the CentOS machine and Windows machine with direct access to the SAN.
