Mover making Plex server unresponsive?


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1 hour ago, Teixeira said:

I have my 'system' share set to cache only, but some data was still on the array.

You should have it set for cache prefer, that way if the files weren't open mover would have automatically put them on the cache where they belong.

Turn on the help on the share settings page for explanation of the cache modes.

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I waited for the full release of 6.7.0 to come out before upgrading from 6.66, where I didn't run into this issue. Since upgrading a couple of weeks ago, I started getting calls about streams crapping out. I've never had these complaints in two years of running this server, and the server is far from resource-starved at 64gb of RAM and 2x8c/16t Xeons.

I, too, have tracked the issue down to the mover. When the mover is running, the entire system's performance grinds. Today, I had to wait about 2m for radarr to even load it's GUI - stopping the mover instantly mitigated the symptoms of the issue.

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  • 2 weeks later...
On 5/29/2019 at 8:19 AM, brainbone said:

I'm not certain if this happened before I upgraded to 6.7.0 as I seldom manually ran the mover when I was on 6.5.x -- though I don't recall it happening before the upgrade to 6.7.0.

 

Same here, upgraded to 6.7.0 and mover now causes Plex to hang, I noticed in TOP the IO wait time is through the roof when mover runs. IO Wait pegs out at 75 - 90%!

I have two LSI cards on a SuperMicro BPN-SAS2-846EL2 expander, each card is connected to 2 ports on the card so there should be plenty of bandwidth. One LSI card is built into the motherboard (running of CPU PCIe) and second card is running off the 8x slot on the motherboard.

 

I don't recall this happening on my older Celeron machine, it was running 6.6.x.

 

Looks like others are having the exact same issue and the symptoms are identical, so that is good...

Edited by coolspot
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I'll add my name to the list of those seeing poor response from unRAID's webgui and Docker containers whenever Mover is running. As I'm still migrating 50TB of data attached via the Unassigned Devices plugin, this is a major bottleneck. I copy about 950GB to my 1TB cache SSD, pause the copy, then manually initiate mover during which the system becomes unresponsive and Plex is unusable. If I just let the copy continue, it gets worse when the scheduled Mover run starts, which is why I pause the copy after each successive fill of the cache SSD.

 

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32 minutes ago, Squid said:

Today's updates to the mover tuning plugin allows you to do that (CPU and I/O priority)

Thanks Squid! You're my hero.

 

I've set CPU priority to "Very Low' and disk i/o priority to "Idle." This seems to have solved all my issues with the mover stalling other processes.

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This issue popped up for me last night and its been bugging me ever since. I have Plex data on an unassigned SSD, was direct streaming/direct playing a file, and I started getting constant hangs while watching a video.

On 6/5/2019 at 6:48 AM, chad4800 said:

It seems that if the video file still resides on the cache drive it streams fine, however if the file has been moved to the array, then I have the lockup/buffering issue while the mover service is running. That would seem to point to Disk I/O contention on the array, not sure. 

Perhaps it was because I was trying to watch a 4K remux, but I still experienced this issue with the file on the cache array. Cache is connected via mobo SATA3, whereas my parities and data drives are connected via a IBM1015/LSI/expander... so I'd think the mover process wouldn't interfere with the cache at all.

Edited by kaiguy
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1 minute ago, kaiguy said:

This issue popped up for me last night and its been bugging me ever since. I have Plex data on an unassigned SSD, was direct streaming/direct playing a file, and I started getting constant hangs while watching a video.

Perhaps it was because I was trying to watch a 4K remux, but I still experienced this issue with the file on the cache array. Cache is connected via mobo SATA3, whereas my parities and data drives are connected via a IBM1015/LSI/expander... so I'd think the mover process wouldn't interfere with the cache at all.

I've experienced this as well. I've tried using a SSD as an unassigned device for Plex, and also on my SSD cache drive within unRAID. I do believe that part of the problem is the Plex clients themselves and will be reporting this to the Plex support forums shortly. I've found that  even with Mover tuning priority set to Very Low and disk I/O priority set to Idle, higher bitrate media still has playback issues and will often get stuck 'buffering'.

 

I believe part of the issue is that the Plex client on most smart TVs have limited RAM to work with. The Plex for LG WebOS client is a prime example of a Plex client that fails often. And surprisingly, even the Plex for Apple TV client often buffers for high-bitrate titles. It makes less sense for the Apple TV 4K as I have a 64GB model and it has plenty of unused storage according to the list of apps under Settings. However the 3rd party Infuse Pro client on my ATV4K rarely experiences a hiccup.

 

My HTPC using either VLC or Zoomplayer also rarely experience the buffering that seems to plague the official Plex clients. I've even played around with CPU pinning with Plex getting 3 out 4 of my hyper-threaded cores (6 threads total) and all other unRAID processes with the 1st core (2 threads). I am planning a hardware upgrade eventually to a system with more CPU cores, but in reality it still seems that the Mover process and disk I/O priority take too many resources to allow for optimal media playback.

 

At least I have work-arounds by using Infuse or my HTPC.

 

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1 minute ago, AgentXXL said:

I've experienced this as well. I've tried using a SSD as an unassigned device for Plex, and also on my SSD cache drive within unRAID. I do believe that part of the problem is the Plex clients themselves and will be reporting this to the Plex support forums shortly. I've found that  even with Mover tuning priority set to Very Low and disk I/O priority set to Idle, higher bitrate media still has playback issues and will often get stuck 'buffering'.

 

I believe part of the issue is that the Plex client on most smart TVs have limited RAM to work with. The Plex for LG WebOS client is a prime example of a Plex client that fails often. And surprisingly, even the Plex for Apple TV client often buffers for high-bitrate titles. It makes less sense for the Apple TV 4K as I have a 64GB model and it has plenty of unused storage according to the list of apps under Settings. However the 3rd party Infuse Pro client on my ATV4K rarely experiences a hiccup.

 

My HTPC using either VLC or Zoomplayer also rarely experience the buffering that seems to plague the official Plex clients. I've even played around with CPU pinning with Plex getting 3 out 4 of my hyper-threaded cores (6 threads total) and all other unRAID processes with the 1st core (2 threads). I am planning a hardware upgrade eventually to a system with more CPU cores, but in reality it still seems that the Mover process and disk I/O priority take too many resources to allow for optimal media playback.

 

At least I have work-arounds by using Infuse or my HTPC.

 

 

The mover is absolutely going to affect cache since it's going to be doing reads off of cache.  So if you have trying to play a 4K remux off cache at the same time the mover is reading from cache I'm not surprised you are having issues.

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Just now, IamSpartacus said:

 

The mover is absolutely going to affect cache since it's going to be doing reads off of cache.  So if you have trying to play a 4K remux off cache at the same time the mover is reading from cache I'm not surprised you are having issues.

But as I and others have mentioned, even using a SSD as an unassigned device experiences the same issue. I do believe it's the Plex client(s) at fault more than Mover.

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  • 2 weeks later...

Any chance this is issue is more related to the rsync application more than anything? The same issue described here happens for me with Plex/Emby using unbalance plugin as well....also rsync. Anyone take a stab at rewriting either plugin to use rclone? I get much better performance on my scripts using rclone for file moving processes.

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  • 2 weeks later...

I am testing unraid as a replacement for my windows server for plex and all the bits that go with it. Having a similair issue where the mover will kill plex - or all docker content - will try the plugin mentioned here to reduce the priority - but also copying data to a share also brings docker containers to a standstill.  Ive tried multiple configs with SSD caches etc, locking the appdata to SSD etc - and no luck in improving performance.  

The current windows server runs a mix of hardware raid for some disks - and flexraid for the rest - flexraid is now pretty much dead as for upgrades and support - but certainly doesn't suffer from what I am seeing here - neither did freenas on the same hardware.

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7 hours ago, bytchslappa said:

Ive tried multiple configs with SSD caches etc, locking the appdata to SSD etc - and no luck in improving performance.  

Go to Tools-diagnostics and attach the complete Diagnostics zip file to your next post. 

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1 hour ago, Squid said:

Have you tried that yet?

No - I guess the main issue I am having - and when the movers runs - copying a file to the array via SMB will bring all dockers to a halt - not just the mover.. even with the docker file running on the cache drive...this is writing directly to the array and not to the cache drive. 

 

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