We're using WHM 64.0 on a CloudLinux 6.9 dedicated host.

We have a scheduled backup configured that backs up each hosted cPanel, as well as the system files.

The backup also FTP's the backup files to an external host after backup. It should prune old backups from the external FTP host. However, we're receiving an error during the prune process. The FTP server is a Windows 2012 Server machine.

Preview of transport errors log: Unable to prune transport “nas-whm” The system cannot remove outdated backups because it cannot read the contents of the directory: /2017-05-11

If we try to validate the FTP destination, we receive the following error:

Error: Validation for transport “nas-whm” failed: Could not list files in destination: “Cpanel::Transport::Files::_perms_str2oct” was given an invalid permissions string: 05-11-17

1 Answer 1


The FTP server is a Windows Server 2012 machine. It was configured to use ms-dos style directory listings for FTP. ms-dos FTP listing are not compatible with the external backup transport in WHM.

To set the global FTP directory output style to UNIX

  1. In IIS Manager, right-click the FTP Sites folder, and then click Properties.
  2. Click the Home Directory tab.
  3. Under Directory listing style, click UNIX.
  4. Click Apply, and then click OK.


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