Oh, I reniced the hog processes +5 (which yields 25 priority) from the beginning. That didn't help. Or just partially: when the load was over 22 the website was still responsive because of that. With 76 load however the spawned apache threads for handling the HTTP requests were just starving. There were 150 of them. Also there were 240 chron jobs related to drupal (49 drupal threads), and we don't even use drupal AFAIK :P
On Feb 20, 12:14 pm, Tilghman Lesher <[email protected]> wrote: > On Mon, Feb 20, 2012 at 11:59 AM, tocsa <[email protected]> wrote: > > The server in our laboratory has some problems. A PhD student is > > running computation which has very heavy I/O load, but no CPU load. > > The lack of CPU load means that there's nothing which would hold back > > the process to hog the hard drive. Many of you are server > > administrators so you know the concept of "server load". If it is > > above 3, then the server is under very heavy load, above 6-7 it can > > happen that you cannot log-in remotely. > > So far my techniques is that I keep an open root console on my desktop > > machine at the university, that console is always alive. Last week I > > saw load above 22. Today I had to take a screenshot, so when I'll be a > > grandpa I can show it to my grandchildren: load above 76. > > > The machine is a server hardware, quad core with 16GB RAM, I don't > > exactly know the HDD subsystem, browsing the /proc I think it's some > > kind of SAS disks. It is running Ubuntu Server LTS. > > > Question: how can I limit the I/O access of a process? > > > I've seen numerous articles on disk quotas, network bandwidth tuning, > > some on CPU load tuning, but no I/O load tuning. > > There's nothing I can see that would do that. However, since what > you're really aiming to do is to avoid resource starvation, why not > re-nice his process? Give it a slightly lower priority, and > everything else will preempt his process when those other processes > need CPU and I/O time. Ask him nicely, and he may even start his next > process with a nice'd priority. -- You received this message because you are subscribed to the Google Groups "NLUG" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nlug-talk?hl=en
