High Swap Usage and Performance Stutter with Ample RAM on Transcoding

[Dalpuri 0]

 

Hello,

I am seeking assistance with a perplexing issue on my media server, which involves unexpected swap usage and performance degradation under heavy load, despite having a large amount of available RAM.

Server Specifications:

• RAM: 126GB
• Swap: 16GB
• CPU: 32-core (No GPU)

Issue Description: While running transcoding operations on Emby, the server’s RAM usage increases to only about 8-10GB, far less than the total available. Strangely, rather than utilizing the abundant free RAM, the system starts to consume swap space. The vm.swappiness is set to 10 to minimize swapping, yet this issue persists.

When the swap usage nears its full capacity of 16GB, I notice that the Emby web interface begins to stutter and the overall performance of the server diminishes. This suggests that the server is resorting to disk I/O for swap file usage, which is significantly slower than accessing physical RAM, causing these performance issues.

Troubleshooting Performed:

• Reviewed system configurations for any potential memory usage limits.
• Monitored system with htop, confirming that CPU cores are maxed out, but RAM is not fully utilized.
• Ensured all system software and kernel are up to date.

I am puzzled as to why the system would favor swap space over RAM when there is plenty of memory available. Additionally, the consequential performance hit when the swap is full is impacting the usability of the Emby service.

Could there be a misconfiguration or a specific application behavior that is causing this? I would greatly appreciate any insights or recommendations on how to resolve this issue and ensure that RAM is fully utilized before swap space is touched, thus avoiding the performance pitfalls of a full swap situation.

Thank you for your time and help. Logs(Giving dropbox link since its more than the limit): Log File (Dropbox)

 

[TMCsw 123]

What happens if you disable swapping (as you don't appear to really need it).

sudo swapoff -a