How to Troubleshoot a Remote Transport Pruning Failure
Last modified: July 29, 2021
Users who store remote backups may encounter an issue where the remote pruning process (deletion) does not complete within the system-allotted time limit. The maximum time limit is 300 seconds per transport process. This document offers solutions to troubleshoot the timeout problem.
Make certain that your FTP server supports the MLSD (Machine List Directory) or LIST commands. If the FTP server does not support these commands, the backup system cannot use the FTP server as a remote FTP server.
Make certain that any hidden files (files that begin with a period (
.)) on the FTP server have write permissions. The backup system can only prune data from files with these permissions.
We strongly recommend that you use Pure-FTPd or ProFTPD on remote FTP servers. Unexpected results may occur with some FTP server software.
- If you use Pure-FTPd, ensure that the
DisplayDotFiles yesstatement resides in the
- If you use ProFTPD, ensure that the
ListOptions -astatement resides in the
- If you use Pure-FTPd, ensure that the
If you use the Very Secure FTP daemon (
vsftpd), ensure that you set the
/etc/vsftpd.conffile. For more information about
vsftpd, read the vsftpd documentation.
Based on your iNotify settings, the system will send an email notification when it encounters a transport error. The email notification shows a preview of the transport error log and includes an attached copy of the transport error log.
The following examples represent transport error code messages in the transport error log, where the directory name
/home/username/backups/2018-05-24 represents the directory name:
cPanel & WHM version 76 and later
The system could not prune the "home/username/backups/2018-05-24" directory due to an error. Read the go.cpanel.net/directorypruning documentation for solutions to successfully prune the directory.
cPanel & WHM version 74 and earlier
If the directory to be pruned "home/username/backups/2018-0524" contains incremental backups with large numbers of files, you may need to remove it manually.
The solutions shown in the next section will help you troubleshoot and fix these issues.
Several different situations may cause a transport error. You will have to diagnose your configuration to determine the appropriate solution.
The directory size is too large
The remote transport process may time out if it tries to prune a very large directory. The following options can help you to solve this issue:
Manually delete the directory from the remote destination
The transport may produce an error if it is unable to prune the directory due to its size. You can manually delete the directory from the remote backup location to troubleshoot this error.
rm command to delete the directory from the remote destination. For example, if you wanted to delete the
/home/username/backups/2018-05-24 directory run the following command:
rm -rf home/username/backups/2018-05-24
Disable the account’s backup
Some accounts may be too large to back up to a remote backup location. You can disable an account’s backup in WHM’s Backup User Selection interface (WHM >> Home >> Backup >> Backup User Selection). You can also use the WHM API 1
toggle_user_backup_state function to disable the account’s backup.
Change the backup type from incremental to compressed
If you are saving the backups for the large-sized account as an incremental backup type, you can change the backup type to compressed to use less disk space.
The rsync backup transport does not accept compressed backup files. If you enable backup compression, you must also change the destination type in your backup configuration to a destination that accepts compressed backup files.
You can change the backup type and the destination type in WHM’s Backup User Selection interface (WHM >> Home >> Backup >> Backup User Selection). You can also use the following WHM API 1 functions to update your backup configuration:
backup_config_set— Sets the backup configuration options (use this to update the backup type).
backup_destination_add— Adds a backup destination.
backup_destination_delete— Removes a backup destination.
The backup drive is too slow
The transport may produce an error if your remote backup location is too slow to process the transport pruning within the system-allotted time of 300 seconds. We recommend that you replace the existing remote backup location with a faster-processing remote backup location.
The transport may produce an error if network issues occur. If this was the case, you can run the backup transport process again manually when the network works properly.
To manually run a backup, run the following command as the
Permission denied error
The transport may produce an error if the following conditions exist on the server:
- A non-
rootuser authenticates to an rsync backup destination.
- Files that the user does not possess write privileges to resides in a cPanel user’s directory.
We recommend that you manually delete the files that the system could not remove from the remote destination’s backup.
You may need to allow write privileges to a file before you delete it. To do this, run the
chmod +w file command, where
file represents the file for which to update permissions.