I was just testing my server after finally finishing the setup more or less and wanted to see how many simultaneous transcoded stream I can play in Plex.

 

For some reason at 4-5 streams, all the streams start buffering and hang there. Watching my CPU utilization is barely even working. My RAM is all cached and gone though.

 

Any ideas what could cause this?

 

Cheers GEN

How are you testing this, from inside your network or outside? Did you let one stream go and see if it buffered before starting another stream? Where are the files stored that you are streaming? How do you have plex configured for your internet connection and streaming quality?

Testing locally. Yes, all stream started playing before starting another one. Files are stored on the server locally on 7200rpm HGST drives connected with a LSI 9300-8i 12GB/s Host bus. These are all blue ray remuxes transcoding down to 4MB 720p streams. The fishy thing is my memory (64GB ECC) is used up by cache (59GB) 900MB free and the rest to the system. That doesn't look normal.

Okay, did some reading, apparently unraid caches most free ram automatically and frees it up when needed. The question of course is if it is all being used up somewhere or simply not being used. I have also read that Plex can transcode in RAM or cache drive (SSD in my case). Where would I be able to access those settings?

Edited March 4, 20179 yr by GENINC

You may want to try the plex forums for answers.

Transcoding to Ram is possible, but it involves both settings and a little tinkering because you need to create a RAM drive.  I'd try to figure out what is going on first.  Was the CPU working hard before the buffering started?  I'd be think it was given full BD remuxes.  Try starting one stream at a time and let things stabilize before adding the next stream so we can see where things break. 

Are you transcoding on the cache drive?

I have already changed the transcoding to /tmp (RAM) to see how this works. I think it is a little faster starting the video but the issue remains. Honestly it is all a little wonky.

I have concluded that I can run 4 streams transcoded to ANY bitrate without hiccup, once I start the fifth everything freezes. Looking at my CPU, Disk usage and LAN, every parameter just goes to zero when the 5th stream starts. Meaning all videos start buffering but nothing is happening with CPU, disk or LAN.

 

My setup is as follows:

 

DUAL CPU E5-2683 v3

64GB ECC RAM

500GB EVO SSD

All HDD's are connected through a 12GB/s host bus.

I think ashman70 has the best idea, try the Plex forums. While it's possible there is an unRAID related issue going on the Plex guys can better help diagnose whatever resource Plex is getting starved for. 

Will do, thanks guys.

here is a weird test to narrow down the issue: install a second plex app. then add streams one at a time to each. If they all work with no issues up to your desired stream count, then plex is the problem. if they don't, then you have an issue with hardware or unRaid. that is assuming that both apps don't try to peg the came core with full utilization, but utilization totals haven't seem to have been an issue so far. (you could pin different cpu's to the different apps I suppose to prevent this from happening.)

I tried installing another docker but it doesn't really work. I have still just the one Plex docker sitting there. On a related note, When I click on the Plex Webui it says "Connection was reset".

8 minutes ago, GENINC said:

I tried installing another docker but it doesn't really work. I have still just the one Plex docker sitting there. On a related note, When I click on the Plex Webui it says "Connection was reset".

Unless you change the port the dockers will fight one another. Here's a thought, on your clients try turning off direct play. Depending on the client I've had to do that, thinking iOS devices in particular. Let the plex transcode everything rather, takes a bit to buffer (seconds) but then is rock solid. Also you haven't mentioned the hardware you're running on. In the docker forum under plex make sure to give them all that info.