Good day. I want to understand the mechanism of the journal of the ext4 file system on the partition with no free space. When the process (apache-tomcat) generating many small entries in the text files (debug log files), then after some time on the disk partition runs out of space. By itself this situation is not bad. But at this point begins the abnormal behavior of the kernel jbd2 process. The tool iotop shows that the process consumes 100% of IO. From the storage system I see the increase in the speed of write data to a disk that does not have space for this writes.

The scenario described above is reproduced on the operating system redhat 6.x (3<=x<=6).