Following a configuration change to the "UserVars.HostdStatsstoreRamdiskSize" setting in the host's advanced settings, the system is experiencing admission failures related to the hostdstats file.

Products

• VMware vSphere ESXi

Issue/Introduction

• Following snippets are observed in /var/run/log/vmkernel.log 

YYYY-MM-DDTHH:MM:SS.019Z cpu78:2104971)WARNING: VisorFSRam: 203: Cannot extend visorfs file /var/lib/vmware/hostd/stats/hostAgentStats.idMap because its ramdisk (hostdstats) is full.
YYYY-MM-DDTHH:MM:SS.019Z cpu78:2104971)WARNING: VisorFSRam: 203: Cannot extend visorfs file /var/lib/vmware/hostd/stats/hostAgentStats.idMap because its ramdisk (hostdstats) is full.
YYYY-MM-DDTHH:MM:SS.019Z cpu78:2104971)WARNING: VisorFSRam: 203: Cannot extend visorfs file /var/lib/vmware/hostd/stats/hostAgentStats.idMap because its ramdisk (hostdstats) is full.

• Executing vdf -h command on the Esxi, hostdstats shows as 100% utilized and we see that the size of hostdstats is set to 1 MB. 

Ramdisk                   Size      Used    Available    Use%    Mounted on

hostdstats                 1M        1M         0B       100%        --

Environment

VMware vSphere ESXi 8.x

VMware vSphere ESXi 7.x

Cause

The host's advanced settings currently specify a ramdisk size of 1 megabyte for the hostd process to store performance and system statistics.

This setting, controlled by the parameter "UserVars.HostdStatsstoreRamdiskSize", overrides the default behavior of using a 0 megabyte ramdisk, essentially disabling the use of a dedicated ramdisk for hostd statistics.

Resolution

To restore the default behavior of using a 0 megabyte ramdisk for hostd statistics on an ESXi host managed by vCenter, follow these steps:

1. Connect to vCenter Server.
2. Navigate to the Host.
3. Click the host and select "Configure".
4. In the host configuration pane, navigate to "System" > "Advanced Settings".
5. In the "Advanced Settings" section, search for the parameter named "UserVars.HostdStatsstoreRamdiskSize".
6. Set the Parameter Value to 0
7. Click OK to accept the changes.
8. This change will be applied after restarting the hostd service

Note: If an out-of-range value is specified, the vSphere Client reports the error: The value entered is not valid. Enter another value.

Steps to Restart Hostd service:

1. Connect to your ESXi host using SSH with your chosen client, log in as "root", and enter the password to access the command-line interface.
2. Re-start hostd service:

   /etc/init.d/hostd restart

5. Verify the hostd service status:

   /etc/init.d/hostd status

Additional Information

For additional support, please reach out to Broadcom Support.