Disk Read & miniDLNA video stutter

[noodlesuk]

Hi All

I've had miniDLNA running on my FreeNAS server (9.2.1.7) for a few weeks, with no issues. As of yesterday I've noticed that whilst watching 720p video, served by miniDLNA over wifi, I seem to occasionally get stuttering where the video pauses. This seems to coincide with FreeNAS disk reads.

Looking at the reporting, there seems to be reads of upto 1.2mb/s on my raid (mirrored) pair, when the stuttering occurs. Maybe not massive, but spikes relative to anything else (see attached). Are there any tools I can use to determine what process is reading the drive at this time? I'm not sure whether the disk read is causing the video stream to stutter, or if the spikes in disk activity are caused by stuttering video. i.e the WiFi dropping in and out and the client then rebuffering or something? Any help greatly appreciated. System is as below:-

HP N36L Microserver
8GB RAM
2x 2TB WD RED HD's, mirrored, no encryption.

 

[dlavigne]

Did you figure this out?

 

[jme]

I'm also having this same problem after having upgraded from 9.2.1.5 to 9.2.1.8. Configuration is 6xWD GREEN 3TB in raidz2 with 16GB ECC RAM, Core i3 processor. I never had this when I was using 9.2.1.5 or earlier versions. Was there maybe some change the default priority of the processes?
Thanks for any help.

 

[cyberjock]

No, the priority shouldn't have changed. Even then, if you are using something like MiniDLNA, it requires almost no CPU power. If you look in top you should see CPU activity is very low. Unfortunately there's far too many factors that could be responsible for the problem you are having. Streaming loads are one of those that you have to make sure that every packet makes it to the destination within a set timeframe or you get skipping and stuff.

If you are trying to stream over Wifi, that's almost expected to perform poorly except in situations where you can be guaranteed of a clean and strong wifi connection along with a video file that is very low in bandwidth needs.

@jme
Unless you have a smoking gun on what to troubleshoot there's not much to go on to help you.

 

[jme]

Thanks for the reply Cyberjock
I'll try to reproduce it keeping an eye on what's shown in the reporting, in top and in the logs. I'll post if I find something strange
I'll also try to stream only through wired connection to see if I can isolate the problem to the network setup.