Thanks for suggestions. I will try to disable some traffics. After the system reboot, I found "oom -killer" in syslog, I assuemd it was caused by blktrace. :-) On Tue, Aug 31, 2010 at 7:32 PM, Alan D. Brunelle <alan.brunelle@xxxxxx> wrote: > On 08/31/2010 02:32 AM, Xuekun Hu wrote: >> >> Hi, Guys >> >> My Linux system (2.6.18, x86_64, RHEL5) only has 1G memory, and I >> would like to use blktrace (1.0.1) to capture 20 minutes of IO traces >> with medium IO traffics. After 20 minutes, system would hang. I think >> at this phase, blktrace is exiting and printing the summary section >> that number of events captured on each cpu. >> >> I'm guessing the system hang due to out of memory. (I can ping the >> system, but can't login). I'm wondering is there a workaround? >> >> Thx, Xuekun >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrace" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > Well, you'd have to prove that the system was out of memory - note that > blktrace statically allocates it's memory at the beginning of the run (or at > least, used to). So it's direct use of memory shouldn't expand over time. > Indirectly - as it puts data out to disk - it could be consuming buffers for > that operation. > > One workaround (to try) would be to go into network mode and send the data > to some other machine to process. Of course, network traffic consumes its > own buffers as well... > > Another option is to limit the traces to collect - if there are only certain > things you are interested in, you could limit collection & saving to just > those traces. [One thing to disable would be the I/O scheduler traffic if > you are not interested in that - I found in the past that some of those > (CFQ) could generate a tremendous amount of traces.] > > Regards, > Alan > -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
