Poor performance when running virtual machines on a local or direct attached SAS storage with IBM HS23 blades

When running virtual machines on a local or direct attached SAS storage with IBM HS23 blades, you experience these symptoms:

• Slow virtual machine I/O performance
• I/O starts as expected, but then decreases
• No errors or events are logged in the vmkernel.log file
• The esxtop command reports high DAVG values during the slow performance

This issue happens when two VIB files are installed, one by the standard ISO provided by VMware and another by the IBM Customized ESXi 5.0 GA Build.
To workaround this issue run these commands in either the DCUI or via an SSH session:
esxcli software vib remove -n ilfu
esxcli software vib remove -n LSIProvider
Restart the ESXi 5.0 host.
This issue does not occur with VMware vSphere Hypervisor 5.0 Update 1 IBM Customized image.
For more information read the following article from IBM