Hello to everyone! I don't know - whether anyboby asked about that or not, but I've not found the solution for my issue by serfing internet. My issue id described here - http://stackoverflow.com/questions/15628546/webshpere-and-qos-logback-log-fi... And I repost it here: We are using WebSphere app server for our application, and "logback" logging framework for managing our log files. Seemed everithing was working fine but recently we detected unacceptable behavior of file rolling. For the first starting of our application on WebSphere rolling log files (by size and by days) works good, but when we stop application - current log file is locked by java.exe(IBM WAS) process and when we start application over again - rolling logs does not work because of previous locking. When I looked on the file throu windows Unlocker i was surprised - there were 2 processes which locks current file. And if we stop app and start it again - there will be 3 java.exe that lock current log file, although in the task manager running only one process. Sometimes I catch OutOfMemory error during such "testing". So that, we have very big log file at the end. (20GB and more) I've found some similar problems but with log4j rolling. And there are no any explanation why it was so - just one was like - log4j is not recommended for websphere. And seems problem not exactly in "logger" at all. So, is there anybody who could answer 2 questions - Why does WebSphere lock file and not release it, when application has been already stopped??? How to release (or say to WebSphere not to lock) locking of the log file when application is stopped in a right way(without using cheats like Unlocker, Task Manager, etc.)? Thanks for attention... any help would be appreciated. regards, Oleg.