Hi,
https://mirror.yandex.ru/ has a broken config april 2020. Old packages have not been deleted and in turn when I rsync with this mirror, it fills my storage space.
I changed mirror to sync with slackware.cs.utah.edu, now it is working perfectly.
I don't speak russian and I am unaware who to contact.
So beware of this mirror for rsync.
Zcoldplayer