Virtual machines might experience slow performance in vSAN 6.5 while running certain NVMe drivers

Products

• VMware vSphere ESXi

Issue/Introduction

• In rare occasions, under high input/output processing conditions you may observe the vSAN disk group going offline.
• In the /var/log/vmkernel file, you see message similar to:

2020-03-30T15:48:43.044Z cpu7:21644947)nvme:scsiIoCompleteCommand:459:vmkCmd 0x43a194105f00[28h I:0x4307df218480 SN:0x168418e0] UNDERRUN 8192/32768

 

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Cause

This issue is caused in the inbox driver.

Note:This is only observed when using the following NVMe devices in vSAN cluster:

• Intel NVMe P4800X
• Intel NVMe P4600/P4500
• Intel NVMe P4610/ P4510 

Resolution

This issue is resolved in VMware ESXi 6.5 EP20 Patch Release ESXi650-202006001.

For more information on downloading patch, see Download ESXi patch and the ISOs for latest relases (372545).