From: "ara.t.howard" Date: 2007-11-09T14:00:28+09:00 Subject: Re: Ruby/Fastcgi going into uninterruptible after random periods of time On Nov 8, 2007, at 9:31 PM, M. Edward (Ed) Borasky wrote: > Processes in the "D" state for significant periods of time tell me > that there *is* an I/O problem. Are these Ruby processes? Are other > processes/kernel threads, for example, "kswapd" or "bdflush" also > in a "D" state? > > If you haven't already done so, install the "sysstat" RPM. That > will give you a marvelous tool called "iostat". Run "iostat -x -t" > with ten-second samples and collect the logs in a file. When your > system starts getting "D" state processes, look at the time stamp > and compare it with the "iostat" logs. If you see one or more disks > with a utilization of 100 percent, you're waiting for disk. > > Another thing to look at is those memory leaks. I don't remember > what Fedora Core 4 used for a kernel, but CentOS 4.5 is a 2.6.9 > kernel IIRC. The memory leaks may be starving the system of memory. > "vmstat" will tell you that -- if you see lots of swap in and swap > out, your memory leaks are making your system thrash. > didn't know about 'D' ed - thx. a @ http://codeforpeople.com/ -- we can deny everything, except that we have the possibility of being better. simply reflect on that. h.h. the 14th dalai lama