Backups from VAMI to FTP/SFTP server fail with ERROR: ftp cmd failed. RC: 21, Err: curl: (21) QUOT command failed with 500

Products

• VMware vCenter Server

Issue/Introduction

• When trying to take backups of the vCenter in the VAMI to a 3rd party FTP/SFTP server we see the backup fail in the VAMI UI
• VAMI backups fail to complete when the FTP/SFTP server does not support required FTP operations or fails during the file transfer phase, leading to incomplete or unsuccessful backups.
• /var/log/vmware/applmgmt/backup.log

  YYYY-MM-DDTHH:MM:SS [MainProcess:PID-xxxx] [Proc::VerifyProcStatusAndGetArchive:Proc.py:158] ERROR: Error at process ComponentScriptsBackup; rc:18.
  YYYY-MM-DDTHH:MM:SS [MainProcess:PID-xxxx] [Proc::VerifyProcStatusAndGetArchive:Proc.py:162] ERROR: stderr:Failed to dispatch component vum backup
  b'curl: (28) FTP response timeout\ncurl: (18) server did not report OK, got 550\n'
  YYYY-MM-DDTHH:MM:SS [MainProcess:PID-xxxx] [BackupManager::main:BackupManager.py:592] ERROR: BackupManager encountered an exception: Data transfer failed due to issues on the remote server. See logs for details. https://FQDN_OF_vCenter/appliance/support-bundle
  YYYY-MM-DDTHH:MM:SS [MainProcess:PID-xxxx] [BackupManager::HandleBackupCleanup:BackupManager.py:466] INFO: Cleaning up the backup job.
  YYYY-MM-DDTHH:MM:SS [MainProcess:PID-xxxx] [FtpStorageIOLib::_process_curl_output:FtpStorageIOLib.py:133] ERROR: ftp cmd failed. RC: 21, Err: curl: (21) QUOT command failed with 500
  , Cmd: ['/usr/bin/curl', '--fail', '-u', 'FQDN_vCenter:****', '--connect-timeout', '120', '--noproxy', '*', '--silent', '--show-error', '-Q', 'dele Folder_where_backup_is_stored_in_FTP/vum.gz', 'ftp://FQDN_OF_FTP-Share/Folder_where_backup_is_stored_in_FTP/']

Environment

VMware vCenter Server 7.x
VMware vCenter Server 8.x

Cause

This issue occurs due to the FTP server rejecting or mishandling of raw FTP commands issued by the VAMI backup process.

Resolution

This issue is not caused by the VAMI backup functionality but by limitations or misconfigurations in the FTP server.

Steps to test VAMI Backup Functionality:

• Reconfigure VAMI to use local storage of vCenter Server for backup, for instruction please follow KB: Performing a Self-Backup of the vCenter for troubleshooting VAMI Backup issues
• Initiate the backup and confirm that it completes successfully.

Steps to test File Transfer between vCenter Server and FTP Server being used to store backup:

• Test transferring large files to the FTP server using curl.
• If transfer fails, review FTP server logs and configuration.
• Update or reconfigure the FTP server as needed and re-test the VAMI backup.

 

 

Additional Information

Network instability or bandwidth fluctuations may also cause FTP session disruptions during large transfers.

If the issue persists, please contact Broadcom Support and reference this KB article for assistance.