Server Version#: 1.24.5.5173
Player Version#: 3.2.20
Im experiencing a very strange issue that I’m unable to resolve. I’ve searched through these posts and one other person had the same problem, but the post was closed without a resolution.
I have been running Plex Server for years on Windows 8.1 and my data store on this desktop is 16TB RAID 5 connected to a RocketRAID 640L card.
Recently I noticed when playing movies 1080p direct via Wired or Wireless, buffering starts to happen after 5-10 minutes into the movie. Sometimes longer before it happens. I initially thought this may be down to bandwidth, so I tried the same movie from my laptop on the wifi, and connected the TV using wired, then wireless. Made no difference and I got the same experience whether I was viewing using my Sony Android TV Plex app or my Windows 10 laptop Plex app.
I noticed that on my Windows 8.1 desktop running the Plex Server, that my disk utilisation was 100%, yet the read and writes speeds were 0 or very little KB/s… ? As soon as the disk runs at 100%, the buffering starts.
If I play the movie directly on the Windows 8.1 desktop, the disk is hardly utilised and no buffering occurs. Same happens if I run the movie manually using Media Player Classic via the network share from my laptop over wifi. Something is differently happen when using plex server to stream my movies, but I’m at a loss as to what is causing this.
During all of my tests, the CPU was hardly utilised and no transcoding was happening as the movies played direct and were supported.
Please help!!! as I’m at a complete loss…
I don’t know what’s causing your issue, but if this also happens when using MPC, how is Plex involved?
Edit - Sorry, I read your comment wrong. Please provide your server logs after you notice this happen? Let me know approximately what time this occurs.
I’ve ran a movie again this morning and within the first 5 minutes, it started buffering. Here are the logs. The time would be between 08:00 till 08:05 am.
Here is a screenshot of task manager. You can see disk 100%, but no read or write access speeds. CPU is always good and never high.
Plex Media Server Logs_2021-11-11_08-04-19.zip (5.8 MB)
I see you have a bunch of old plug-ins still installed. I would go ahead and remove all of these, just in case one of them is still trying to run and causing an issue.
I’m not seeing anything else going on with PMS.
I’ve tried to uninstall all plugins and I get an error message ‘This plugin could not be uninstalled.’ The issue with buffering and my disk going to 100% is definitely down to plex due to the process of elimination I’ve completed. If the movie runs completely fine using Media Player Classic as the player over a network share or ran locally from the Windows 8.1 device running Plex Server, this indicates a Plex issue. It only happens when running the movie via the Plex player from the TV, Laptop or Mobile.
What can be suggested then, because I’ve been using Plex for many years with a life time Plex Pass? Never had this issue before. Is there someone else who can assist if you have reached the peak of your troubleshooting deductions. Should I run the movie for longer? Reinstall Plex Server? Upgrade my OS to Windows 10? I’ve come across others having this same problem in these forums, but no conclusion and the post is closed… Please don’t let this be another example of that happening.
Please help!
Here is a new log to investigate. Ran movie between 17:00 till 17:50. you can see in the logs that the audio is transcoding, so it may have something to do with this? Not sure what the best practise is for the temporary folder location used for transcoding i.e. same drive has movies or c:. The c:\ is SSD, does this have any impact. Plex Media Server Logs_2021-11-11_17-49-03.zip (5.2 MB)
Just go delete the bundles and restart PMS.
Upgrade my OS to Windows 10
That wouldn’t hurt to rule out issues with 8.1.
Not sure what the best practise is for the temporary folder location used for transcoding
That shouldn’t matter since the load is on F.
the audio is transcoding, so it may have something to do with this
Can you try playing something where no transcoding is occurring? Also try one with the video transcodes but not the audio.
I’ve manually removed plugins from folder director and restarted Plex. I’ve then played the following films with the following results.
Sony X85J Andriod TV Plex App
The Burbs - DVD Stero AC3 no transcoding
Batteries not included - 1080p DTS-HD 5.1 no transcoding
47 Meter Down: Uncaged - 1080p TrueHD 5.1 Audio transcoding / Video Copy (HEVC)
1917 - 1080p 5.1 AC3 Dolby Atmos UNABLE TO PLAY FILM between 20:08 to 20:11
2012 - 1080p DTS-HD 5.1 no transcoding
After Earth - 1080p DTS 5.1 no transcoding
Alien: Convenant - 1080p DTS-HD 7.1 no transcoding
Star Trek Beyond - 1080p TRUEHD 7.1 Audio transcoding / Video Copy (H264)
Transformers: Dark side of the Moon - 1080p TRUEHD 5.1 Audio transcoding / Video Copy (H264) BUFFERING/100% Disk 20:43
Dune - 4K 5.1EAC3 no transcoding
The Suicide Squad - 4k HDR 5.1EAC3 no transcoding
Cruella - 4K HDR TRUEHD 5.1 Audio transcoding / Video Copy (HEVC)
Star Trek - 1080p TRUEHD 5.1 Audio transcoding / Video Copy (H264)
For some reason Transformers seems to be an issue, and 1917 will not play at all. Everything else works fine, and I could not find a common problem with audio types. I have watched these films via Plex with no problems before.
see log in case this helps:
Plex Media Server Logs_2021-11-11_21-06-55.zip (4.8 MB)
I will upgrade to Windows 10 as a last resort, but not before everything else has been eliminated. Let me know if you find anything in the logs.
Are you still seeing the 100% disk utilization?
Only with Transformers film out of the ones I tested. 1917 didn’t even play. I only played the movies for 5 minutes, but this did happen with the other transformers films as well. I’ve started watching them again from the first one. It happened a lot further along in the film though. Unlike the one I tested in my list happens in 5 minutes from the start, everytime.
For 1917, it is trying to direct play the file. However, it is not able to analyze the audio properly and this is causing the playback to fail. I’ve seen this happen when a file is encoded badly. You can try to fix it by remuxing the streams into a new file.
I see for Transformers where PMS is transcoding audio and copying video. Plex’s transcoder works in bursts and generates a small amount of data at a time. It takes breaks when it’s not needed. I see it taking a break and then going back to work, but when this happens, it’s not generating more data. So looks like PMS trying to generate these temporary files is either being stopped due to the disk activity, or the transcoder is causing this disk activity and unable to continue, but they do seem to be connected.
Since this only happened with this 1 file, and the movie from your earlier test, I’m leaning towards something with those files or maybe your Raid array. As a test, try copying that movie to your C drive and create a test library with that directory. See if that plays, if it does, then it might be the array. If that also doesn’t work, it could be the file.
Hi, I have remuxed 1917 and removed one of the audio streams and left the Truehd and now works. Not sure why this worked before via Plex. maybe a recent update to the transcoder has made it more sensitive to some audio streams. Transformers still buffers on all of those films, but the ‘Dark side of the moon’ is the worst. Have they been any updates recently to the transcoder in recent updates?
May be worth using something like DiskMon (link below) to monitor the activity on the F: drive whilst this is happening. Make sure you set up a filter to only monitor the F: drive and only have it running whilst you are testing (otherwise the volume of log info will be enormous).
This should show if a disk access is being deadlocked or held up by something creating a disk io queue
Plex has updater the transcoder in PMS 1.25.0, but you are not using that. Maybe update and give it a try to see if it may have fixed these issues.
Hi David,
I have ran the tool whilst this happened and read and write access is still happening. See attached.Diskmon.LOG (154.4 KB)
Hi MovieFan, where can I locate the up to date version of the transcoder?
In Plex Web, go to the General settings page for your server. At the bottom, change the update channel to Beta, save, search for update.
Or download from our website and update manually. Media Server Downloads | Plex Media Server for Windows, Mac, Linux, FreeBSD and More
I was just about to post, found it by selecting Beta. I’m trying this now and will keep you posted. Just saw the hardware acceleration settings for transcoding, so I’m also going to update to the latest Nvidia drivers if this beta doesn’t work. I says that CPU should be used if Acceleration isn’t compatible, but you never know. I think it has been sometime since I last updated these drivers and as PLex is updating, this may have been left behind.
Here is where I’m at. I’ve updated the drivers, installed the latest Plex Server version Beta 1.25.0.5220. Still no joy. I’ve unchecked ‘Use hardware-accelerated video encoding’ and ‘Use hardware acceleration when available’, still no joy.
Just tried to play The Matrix, as this is TRUEHD 5.1 (same audit as transformers) however, the video format is VC1. Each time I run it, Plex Server crashes. Is this because I’m now running on Beta. This experience of Plex crashing is new?
Hi @Guru_Panda - This to me would be a bit of a concern. You shouldn’t be seeing 100% disk usage whilst there are no read / writes happening. That’s essentially something that is kinda impossible!
So to me, that could either be Windows misinterpreting your RAID controller, or maybe even an indication of a problem with either the RAID controller on the Array itself.
I appreciate that you can see the behavior occur when you start using Plex, but in theory, that is only because Plex is accessing the Array.
The thing that sticks in my mind is, why does Windows report 100% usage whilst there are no read / writes happening, and that in itself may be a clue…
1 Like
