When using Plesk you may face difficulties while restoring something from the website or server backup files because of these relatively unknown .tzst files which you find inside them.
TZST or ZStandard is a compression algorithm which was first released back in 2015 by an engineer and data compression expert Yann Collet. While ZStandard originally was developed for Facebook, Yann open sourced it with a noble cause – as a “contribution to the world”. TZST offers much faster compression and better compression rates than GZIP/DEFLATE, therefore it was logical for Plesk to replace the compression method for backup and restore operations with a release of Plesk Obsidian 18.0.40 at the end of 2021.
Therefore it is not recommended to switch back to the old GZIP/DEFLATE compression method because it will certainly degrade the performance of the web server. Moreover this old compression method for backups is also at danger of being removed completely in future releases of Plesk.
How to change Plesk backup file format from TZST back to GZIP/DEFLATE
First login to your Plesk server via SSH as a root user and open the Plesk configuration file (panel.ini) by using this command:
plesk conf panel.iniPress the [INSERT] key to edit the file contents and find the [pmm] section. Append or replace the compressionMethod directive to deflate. It should look like this:
[pmm]
compressionMethod = deflateExit the editing mode by pressing an [ESC] key. Type in the console :wq! afterwards and press enter to save the file and exit the file editor.
The old compression method will be applied immediately for the next backup tasks (no server restart is necessary), however keep in mind that the backup files created before the change will not get converted to the GZIP format.