I have run a file server on a CentOS 5.8 final server.
My only concern at the moment is what appears to be intermittent but continuous high disk I/O activity causing a general slowdown because of jbd2/sda2-8 process.
jbd2/sda2-8 is making use of /dev/sda2, which is the 2nd partition of the first harddrive (IE: root partition).
More info: using "iotop" the culprit appears to be "jbd2/sda1-8" making writes every second, which appears to be a kernel process associated with journaling on the ext4 filesystem, if my googling around is correct.
I see "jbd2/sda2-8" appearing here every now and then, but certainly not every 3 seconds.. when idle, it appears about 1 or 2 times per minute. When I'm using the system, it appears more frequently.
ATOP results:
http://grabilla.com/02b14-8022db2e-4eb9-4f10-8e10-d65c49ad7530.png
IOTOP results:
http://grabilla.com/02b14-cf74b25d-4063-4447-9210-7d1b9b70e25b.png
HTOP results:
http://grabilla.com/02b14-ad8cad0e-89b0-46d3-849d-4fd515c1e690.png
jbd2/sda2-8 is the processes I see with iotop making writes on disk even though it's not in use at all.
Does someone has any idea how could I solve the high disk usage caused jbd2/sda2-8 process?
Best Answer
I don't know if this is helpful, but we had a similar problem which turned out to caused by one of the disks in our RAID array starting to fail. This meant that every write was taking many times longer than it should have been.
We eventually found it when we rebooted and the RAID controller finally detected the issue, but we could have got an idea from checking the RAID logs.
I hope that helps (this is my first attempt at an answer here).