In response to Wulf ():
"Sharing violation on path" means that something was trying to use and lock that file while it was t...
Well, there wasn't any issues in latest 15 months. Just checked, every single log file has last modification time at 23:58-23:59. And i didn't really changed anything lately. The only way i interfere with logs is opening them via WinSCP, and i never pressing "save" button. Can it be caused by upgrade of the Unity to 2019.1, or oxide logging implementation is completely written by yourself? I also had one issue, that -logfile didn't created any logs, until i switched from relative to absolute path, and then it worked fine.

Unity logging has been changed in 2019.1, as you can see from the patchnote:
Editor: Added a fix for consistent logfile option handling for all desktop platforms, the Editor, and the Player. This improves the handling of edge cases and scenarios with logfile parameter. (900754, 960012, 1068907)​
And also some other changes, related to logging: https://unity3d.com/ru/unity/whats-new/2019.1.0