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

Products

• VMware vSphere ESXi

Issue/Introduction

When running virtual machines on a local or directly 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.

Environment

• VMware vSphere ESXi 5.1
• VMware vSphere ESXi 5.0
• VMware vSphere ESXi 5.5

Cause

This issue occurs when two VIB files are installed, one by the standard ISO provided by VMware and another by the IBM in their customized image.

Resolution

To work around this issue:

1. Run these commands in either the DCUI or via an SSH session:
   
   # esxcli software vib remove -n ilfu
# esxcli software vib remove -n LSIProvider (For ESXi 5.0)
# esxcli software vib remove -n lsiprovider (For ESXi 5.1/5.5)
    
2. Restart the ESXi host.

Note: This issue does not occur with VMware vSphere Hypervisor 5.0 Update 1 IBM Customized image.