Upgrading or installing ESXi host using stateful auto deploy boot fails to complete with error "cannot be unmounted. Reason: Busy"
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Upgrading or installing ESXi host using stateful auto deploy boot fails to complete with error "cannot be unmounted. Reason: Busy"

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Article ID: 381387

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Updated On: 06-23-2025

Products

VMware vSphere ESXi VMware vCenter Server

Issue/Introduction

  • Installing or upgrading ESXi hosts using vSphere Auto Deploy with stateful boot fails with error "cannot be unmounted. Reason: Busy".
  • In /var/run/log/syslog.log on the ESXi host the following entries can be found:
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread: Core dump file is enabled. Disabling it
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread: Shutting off coredump file: 0:True
    <timestamp> In(14) hostprofile[2099609]: opID=MainThread: Now caching to disk: t10.ATA_____#########################________________________###########
    <timestamp> Er(11) hostprofile[2099609]: opID=MainThread: EngineModule::ApplyHostConfig. Exception: ("Errors: \nVolume '########-########-####-############' cannot be unmounted. Reason: Busy\n", b'')
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread: EngineModule::ApplyHostConfig. Backtrace:
    <timestamp> Wa(12)[+] hostprofile[2099609]:
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread:    File "/lib64/python3.8/site-packages/hostprofiles/tests/tools/hpcliModules/engineModule.py", line 553, in ApplyTaskList
    <timestamp> Wa(12)[+] hostprofile[2099609]:
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread:    File "/lib64/python3.8/site-packages/hostprofiles/pyEngine/applyConfigSpec.py", line 4724, in ApplyHostConfig
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread: Adding missing key EsxcliError.summary
    <timestamp> Wa(12) hostprofile[2099609]: opID=MainThread: excObj is of unknown type: <class 'esxutils.EsxcliError'>
    <timestamp> In(14) hostprofile[2099609]: opID=MainThread: Cleaned up Host Configuration
    <timestamp> In(14) hostprofile[2099609]: opID=MainThread: /sbin/applyHostProfile sending boot msg to console: Applying Host Profile task list...Error
    <timestamp> Er(11) hostprofile[2099609]: opID=MainThread: while applying tasks: (vmodl.fault.SystemError) {

 

  • In /var/run/log/vmkernel.log following log entries are seen : 
    YYYY-MM-DD HH:MM:SS  Wa(180) vmkwarning: cpu36:2102413)WARNING: VC: 2445: unmounting opened volume ('######-########-####-############' 'OSDATA-######-########-####-############') with ref 3 is not allowed.
    YYYY-MM-DD HH:MM:SS  In(182) vmkernel: cpu36:2102413)FSS: 9877: File fdmDump.log, fhID: ######, is opened by world: <world_id> - fdm
    YYYY-MM-DD HH:MM:SS  In(182) vmkernel: cpu36:2102413)VC: 2716: Unmount volume #### ## # ###### ######## ####### ###### : Busy



Cause

When the chosen system cache partition is in use, it cannot be reformatted/unmounted. The stateful install or system cache fails due to one of the following causes:

1. The partition is used by OSData 
2. A log file is hardcoded to some file path of that partition

Resolution

This issue has been resolved in vCenter Server 8.0 U3e, please patch the vCenter Server to 8.0 Update 3e Build 24674346. 
Reference : VMware vCenter Server 8.0 Update 3e Release Notes 

 

Additional Information