Ispmanager splits backups to smaller parts. Usually limit of one part is 500Mb.
In that case backup directory consist many files. For example:
2023-03-12.mysite.info
2023-03-12.mysite.tgz
F2023-03-12.mysite.tgz.part1
F2023-03-12.mysite.tgz.part2
F2023-03-12.mysite.tgz.part3
F2023-03-12.mysite.tgz.part4
F2023-03-12.mysite.tgz.part5
F2023-03-12.mysite.tgz.part6
Although it's not obvious but actual data is stored in files .part1-.part6. To make real archive we should concatenate all part files in one.
How to make one file from ispmanager's multi files archive?
If you want to make one single tar file just fill form bellow: