I was running top on my server and noticed kjournald seemed (to me) to have a high cpu time. My server has been up for ~21 days and I have never noticed triple-digit minutes usage of kjournald before.
Is this normal of Ubuntu 8.04 or do I need to worry about something going wrong on my system?
kjournald is invoked pretty much on all disk operations, so it's not that strange that it has a lot of CPU time, specially if your server has many write operations. Nothing to worry about, IMO.
Long explanation: kjournald is the kernel thread responsible for journaling on ext3 file systems. You will have one per mounted ext3 FS. On busy hosts, where there are many disk writes commited to the journal and then to the disk and depending on the journaling strategy, it can be quite resource hungry. Take a look on this doc to read a little more about it.
