Avg log write time (log_writer_task) <duration> ms, <number_of> writes, <number_of> pages
Avg log write time (dev_thread) <duration> ms, <number_of> writes, <number_of> pages
The physical writing of log entries take too long. There is the risk of a bottleneck.
Check the reads and writes in the disk area or device on which the log volumes are located. If possible, only the log entries should be made here, and no other reads or writes. In certain circumstances, you may need to move the log volumes to a quicker device.
Concepts of the Database System, How Databases Log Data Changes