At 01:56 AM 4/1/2009, Tom Metro wrote: >mythtv:/etc# iostat -dmx >Linux 2.6.24-23-386 (mythtv) 04/01/2009 > >Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s >avgrq-sz avgqu-sz await svctm %util >sda 16.79 13.66 19.01 1.50 0.14 0.06 >20.15 0.02 1.00 0.82 1.67 >sdb 16.83 13.65 19.01 1.51 0.14 0.06 >20.15 0.02 1.12 0.90 1.84
In a stuttering state: # iostat -dmx Linux 2.6.18-92.1.18.el5 (glutton.home.sinister.net) 04/02/2009 Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util sda 0.41 13.61 2.17 5.93 0.03 0.08 26.28 0.29 35.16 1.25 1.01 sdb 0.02 0.00 0.00 0.00 0.00 0.00 20.44 0.00 3.47 2.48 0.00 sdc 0.16 0.05 1.99 1.56 0.19 0.10 167.25 0.04 12.46 7.05 2.50 >In particular you want to look for differences in the last 3 >columns, and make sure the last one isn't getting close to 100%, as >that indicates your I/O is saturated. > >Having iostat poll for these statistics every few seconds (see the >man page) while the problem is occurring might also turn something up. Yeah, I've tried that, but still no indicators I can find. >What purpose do these two drives serve in your system? sda - core OS drive, repository for backups from other systems that run at 2 am (and otherwise don't touch it), zomeminder database sdb - old myth drive, still ext3 from previous experiments sdc - new (current) mythtv drive, which is used for nothing but mythtv as it's data store. >What about the non-stuttering baseline? Though that seems adequate >for smooth payback. similar. When I change it back to the GB switch I get numbers wildly higher (like two orders of magnitude), odd as the hauptpage device is only 100 mb. >I didn't do a side-by-side comparison of the other data, but you >should, if you haven't already, and post anything you think might be >notable differences. Yeah, the problem is I can't find any notable differences that lead me to further clues *sigh* The biggest indicator I can find that points back to somewhere in mythtv and it's interaction with the mvpmc is that when I use the mapped drive in the mvpmc (with cifs) and play a mpg from there (on the same drive as the mythtv data) it plays smoothly. For recorded shows through myth I usually see in the mvpmc stats ~ 5 mb/sec, where playing those videos I see about 6 mb/sec, with no stuttering. Rick > -Tom ------------------------------------------------------------------------------ _______________________________________________ Mvpmc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mvpmc-users mvpmc wiki: http://mvpmc.wikispaces.com/
