Problem with Purge via GUI at CentOS: it deletes all backup sets

I use D2 at CentOS for a first time. I setuped backup. After days I solved to see compares between current an previous backups. I saw very changed and two log files:

~ /home/bitrix/ext_www/
~ /home/bitrix/www/log_verylonffilename.txt

I decided to purge in. So I pressed “Command line”, chose “Purge”, Set in Parameters:

And deleted all excludes in params.

After this operation the files in backup sets was deleted except these too (what I wrote above).

What I did wrong?

Is it a bug??? Who can answer me?