ESXi host logs "IpmiIfcRhGetOS_Sysname: retrieve sysname failed short buffer read"

Products

• VMware vSphere ESXi
• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x

Issue/Introduction

The following error messages are continuously logged in /var/log/hostd.log on the ESXi host:

IpmiIfcRhGetOS_Sysname: retrieve sysname failed short buffer read (18)
IpmiIfcRhGetOS_Name: retrieve os_name failed short buffer read (18)
IpmiIfcRhGetOS_Version: retrieve os_version failed short buffer read (18)

When executing the localcli hardware ipmi bmc get command from the ESXi command line, system information fields such as Hostname Reported, OS Name Reported are either blank or not displayed correctly.

Environment

VMware vSphere ESXi 7.0
VMware vSphere ESXi 8.0

Cause

This issue occurs due to an implementation difference (incompatibility) in the IPMI communication format between the ESXi host and the BMC (Baseboard Management Controller) firmware of certain server hardware.
When ESXi requests system information from the BMC, it has been observed that some BMC firmware environments return a response with a data structure that does not conform to the IPMI specification.
When the ESXi IPMI driver parses the received data, this structural discrepancy causes ESXi to misinterpret fields such as the data length. As a result, ESXi attempts to request subsequent data blocks from the BMC that do not exist, leading to a "short buffer read" error and the interruption of the system information retrieval process.

Note: This is a cosmetic issue. There is no impact on virtual machine operations, network connectivity, or storage performance. Additionally, hardware sensor monitoring (SDR) for components like temperature and power functions normally, as it utilizes a different polling mechanism.

Resolution

As this is a purely cosmetic issue, these error messages can be safely ignored.

To fundamentally resolve this issue, a firmware update provided by the server hardware vendor (OEM) is required.
Contact your hardware vendor to upgrade to the latest BMC firmware version that features improved compatibility with the response format for IPMI system information retrieval commands.

Workaround
If an immediate BMC firmware update is not feasible, adjusting the string composition (padding) registered to the BMC from ESXi might circumvent the parsing error conditions and stop the error logs.

Perform the following steps:

1. Log in to the ESXi host as root via SSH.

2. Run the following commands to overwrite the cached strings on the BMC.
   [IMPORTANT] The specified string must begin with a single half-width space and be padded so that the total length is exactly 32 bytes (32 characters).

   Example of overwriting Sysname (Hostname):
   localcli hardware ipmi bmc set -H " XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
or
localcli hardware ipmi bmc set -H " esxi-host-01                   "


   Example of overwriting the OS Name:
   localcli hardware ipmi bmc set -n " XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
or
localcli hardware ipmi bmc set -n " VMware ESXi                    "

   Example of overwriting the OS Version:
   localcli hardware ipmi bmc set -v " XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
or
localcli hardware ipmi bmc set -v " 8.0.3                          "
   
   
3. After executing the commands, verify that the error messages have stopped logging in hostd.log.
   
   
4. Run the following command and verify that each field has been updated with the specified string:
   localcli hardware ipmi bmc get

Additional Information

ESXi ホストで "IpmiIfcRhGetOS_Sysname: retrieve sysname failed short buffer read" エラーが記録される