Unable to create a backup: Cowardly refusing to create an empty archive

Symptoms

• Backup is created with the following warning:

  PLESK_WARN: Not all the data was backed up into /var/lib/psa/dumps successfully. Total space: 915.00 GB; Available space: 857.00 GB; Mounted on: /. /usr/lib/plesk-9.0/sw-tar: Cowardly refusing to create an empty archive Try '/usr/lib/plesk-9.0/sw-tar --help' or '/usr/lib/plesk-9.0/sw-tar --usage' for more information.

• Tar 1.29b1.1 package is installed:

  # dpkg -l | grep tar
  ii tar 1.29b-1.1 amd64 GNU version of the tar archiving utility

• Plesk Onyx 17.8 is installed in Debian 9 or Ubuntu 16

Cause

This error message is caused by a bug in Tar 1.29b-1.1 package used by Backup Manager process.

This software issue has been identified with the bug ID #PPPM-9811 which is planned to be fixed in upcoming updates.

Resolution

Subscribe to this article to get a notification once the bug fix will become available.

As a workaround:

1. Connect into the server via SSH

2. Backup Storage.pm and TarBundle.pm files:

   # mv /opt/psa/PMM/agents/shared/Storage/Storage.pm{,.bak}
   # mv /opt/psa/PMM/agents/shared/Storage/TarBundle.pm{,.bak}

3. Download and apply fix with the following commands:

   # wget -O /opt/psa/PMM/agents/shared/Storage/Storage.pm https://support.plesk.com/hc/en-us/article_attachments/360019874834/Storage.pm
   # wget -O /opt/psa/PMM/agents/shared/Storage/TarBundle.pm https://support.plesk.com/hc/en-us/article_attachments/360019874854/TarBundle.pm