On Tuesday 13 September 2016 20:09:26 Miles Fidelman wrote: > Hi, > > Lately, our server has been showing high loading, but top shows that the > CPU is mostly in wait mode, and iotop shows low disk i/o traffic.
How do you know the load is high? Where is the indication coming from? > Usually, the system shows high load when either > > a. Someone is indexing our web server (which shows up as CPU load on > apache). > > b. Our list manager is processing a bunch of traffic (most of the load > comes from spam and virus filtering - which shows up as cpu load on > amavisd, and clamd, as well as a lot of disk i/o). > > The one place I see this effect behavior, if for email clients accessing > IMAP - I've been seeing timeouts, and exceptionally high delays to load > an inbox, or move stuff to the trash. > > This pattern is new - and there's really nothing that I've changed in > terms of configuration or loading that I can see. > > So... any thoughts? Any diagnostic approaches? Could the heat sink or fans be clogged with dust? If heat can't be extracted properly, the CPU will lower its frequency and appears sluggish. The fan will turn at top speed too. I'm interested in more opinions and diagnostic tools too because my laptop suddenly became very slow and unresponsive yesterday until I restarted it. top was showing a mostly idle cpu but kde system activity was displaying a lot of "disk sleep". The computer was fast again if I stopped firefox and libreoffice calc. It went slow again if I started any of them. Restarting the computer solved the problem. Frederic
