vCenter Alarm “Host Connection and Power State” Triggered Due to hostd Service Exiting with Code 127

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi host briefly shows as 'Not responding' in the vSphere Client but quickly returns to normal.
• Alarm 'Host Connection and Power State' is triggered.
• /var/run/log/syslog.log reports hostd exited with code 127.

YYYY-MM-DDTHH:MM:SS.SSSZ watchdog-hostd[xx]: ‘hostd ++min=0,swapscope=system’ exited after xx seconds 127

• /var/run/log/hostd.log reports dynamic libraries are being loaded just before the restart.

YYYY-MM-DDTHH:MM:SS.SSSZ info hostd[xx] [Originator@6876 sub=Libs opID=xxxxxxxx] PluginLdr_Load: Loaded plugin 'libvmiof-disk-spm.so' from '/usr/lib64/vmware/plugin/libvmiof-disk-spm.so' 
YYYY-MM-DDTHH:MM:SS.SSSZ info hostd[xx] [Originator@6876 sub=Libs opID=xxxxxxxx] PluginLdr_Load: Loaded plugin 'libvmiof-disk-vmwarevmcrypt.so' from '/usr/lib64/vmware/plugin/libvmiof-disk-vmwarevmcrypt.so' 

• Note: The libraries loaded may vary and are not always the same as shown above.
• Temporary disconnections of the ESXi host from vCenter Server may occur.

Environment

• VMware vSphere ESXi 7.0.x
• VMware vSphere ESXi 8.0.x

Cause

• This issue originates from a bug in older versions of the GNU C Library (glibc).
• Under specific conditions—particularly when dynamic libraries are loaded simultaneously with thread creation and termination—a rare race condition may occur.
• This race condition can cause the hostd service to exit unexpectedly with exit code 127.

Resolution

• This issue has been resolved in ESXi 8.0 Update 2 (U2) and later releases.
• There is currently no workaround available for affected earlier versions.
• Although the hostd process may crash unexpectedly due to this issue, it is automatically restarted by the system.
• As a result, there is no impact on running virtual machines during such events.