On Jul 16, 2013, at 8:59 AM, shahzaib shahzaib <shahzaib...@gmail.com> wrote: > Hello, > > We're using nginx-1.2.8 to serve large static files for video > streaming. However all nginx worker_processes are in "D" state and HDD I/O > utilization is 99%. > […] > [root@DNTX010 ~]# iostat -x -d 3 > Linux 2.6.32-358.6.2.el6.x86_64 (DNTX010.local) 07/16/2013 > _x86_64_ (8 CPU) > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz > avgqu-sz await svctm %util > sda 30.28 177.37 260.32 2.96 38169.26 1442.70 150.46 > 2.29 8.70 3.52 92.78 > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz > avgqu-sz await svctm %util > sda 4.33 0.00 544.00 0.00 34376.00 0.00 63.19 > 43.83 75.25 1.84 100.00 > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz > avgqu-sz await svctm %util > sda 9.00 6.33 547.67 0.67 34637.33 56.00 63.27 > 48.01 86.20 1.82 100.00 > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz > avgqu-sz await svctm %util > sda 0.00 0.67 568.00 2.33 36024.00 29.33 63.21 > 54.98 101.10 1.75 100.00 > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz > avgqu-sz await svctm %util > sda 0.00 4.33 560.33 1.33 35712.00 45.33 63.66 > 37.20 65.06 1.78 100.00 >
You are likely hitting the IOPS limit. 550r/s is quite enough to saturate 4xSATA 7200 in RAID10. There are reads of 64 of something per request in average. I'd first look at what does something designated as "rsec/s" exactly mean in linux terms here. -- Sergey Kandaurov pluk...@nginx.com _______________________________________________ nginx mailing list nginx@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx
