vCenter Backup fails in combination with Supervisor Cluster backup enabled - backup logs showing "ERROR: Failed to write backup content: [Errno 32] Broken pipeException"

Products

• VMware vSphere Kubernetes Service

Issue/Introduction

Backup of vCenter fails when backup for "Supervisor Control Plane" is enabled in VAMI

 

 

 

- vCenter backup without Supervisor is working well

- There is enough free disk space available on the Supervisor control planes (>=20% free)

 

vCenter backup logs show:

/var/log/vmware/applmgmt/backup.log

2025-07-30T15:48:25.66 [20250730-154700-24674346] [ComponentScriptsBackup:PID-1676206] [Log::run:Log.py:64] ERROR: Failed to write backup content: [Errno 32] Broken pipeException ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>
2025-07-30T15:48:25.67 [20250730-154700-24674346] [ComponentScriptsBackup:PID-1676206] [Log::run:Log.py:64] ERROR: BrokenPipeError: [Errno 32] Broken pipe
2025-07-30T15:48:25.236 [20250730-154700-24674346] [ComponentScriptsBackup:PID-1676206] [ComponentScripts::ComponentScriptsBackup:ComponentScripts.py:106] ERROR: Component backup command "/etc/vmware/backup/component-scripts/wcp/supervisors_backup_restore.py --backup" failed 120.
2025-07-30T15:48:25.236 [20250730-154700-24674346] [ComponentScriptsBackup:PID-1676206] [ComponentScripts::ComponentScriptsBackup:ComponentScripts.py:135] ERROR: Error during component supervisors backup Underlying process status. rc: 120

 

SFTP server logs show messages that indicate a connection timeout:

Example for a Bitvise SSH server:

<event seq="9095" time="2025-08-26 21:01:38.854350 +0200" app="BvSshServer 9.32" type="Info" name="I_SFS_TRANSFER_FILE" desc="Virtual filesystem: transfer file.">
    <conn id="2118" winSesId="C2102" service="SSH" remoteAddress="############:56384" virtualAccount="############" windowsAccount="############" winSes="existing" cacheUse="early"/>
    <channel type="session" id="1"/>
    <sfs moduleName="FlowSfsWin" mountPath="/vCenterBackup295" code="90000" desc="File transfer ended.">
      <parameters path="############\S_8.0.3.00500_20250826-190012_\supervisors.gz" timeMs="60013" bytesRead="0" bytesWritten="0" readRangeOffset="0" readRangeLength="0"    writeRangeOffset="0" writeRangeLength="0" createdNewFile="true" resizedFile="false" startSize="0" finalSize="0" endedBy="Cleanup" download="none" upload="none"/>
      <help message="File transfer ended by connection cleanup; file transfer may not have completed as intended."/>
    </sfs>
</event>

 

Environment

vCenter 8.0U3  

Cause

vCenter including Supervisor backups might require higher timeout values on the SFTP server side

Resolution

Increase the connection timeout values on the SFTP server