log\FileTarget $rotateByCopy

Whether to rotate log files by copy and truncate in contrast to rotation by renaming files. Defaults to true to be more compatible with log tailers and is windows systems which do not play well with rename on open files. Rotation by renaming however is a bit faster.

The problem with windows systems where the rename() function does not work with files that are opened by some process is described in a comment by Martin Pelletier in the PHP documentation. By setting rotateByCopy to true you can work around this problem.