Limiting RAM when using Transmission

[JGMan]

Hey All,

ASUS Merlin 388.2_2 on RT-AX88U

I’m trying to keep the RAM usage under control when I use transmission via entware. I have a 2GB SWAP file setup and I’ve configured transmission to use my 256GB pen drive attached. Downloads do complete successfully.

400MB (40%) free RAM before downloading a torrent. Once the torrent starts, it eats the RAM up until 97% utilised.

I’m assuming the torrent is being downloaded into RAM, then either using the SWAP file, or copying direct to the destination. This is a problem, as even when the torrent is done, the RAM is permanently full until I remove/trash the download. Assuming RAM at 97% will be having a negative impact to other services on the router, including WiFi

I’ve tried changing the “cache-size-mb”, “peer-global-limit” and “peer-limit-per-torrent” but no difference.

Have I got a configuration error here? Is there a way to download straight to storage/SWAP, or even just restrict how much RAM transmission can use?

Thanks in advance!

 

[bennor]

Sounds like a similar issue others have experienced, and commented on, when writing files to a USB device attached to the router. The RAM usage goes to 97% and stays there for a while or until the file is deleted or the cache is otherwise emptied out. Some have indicated the router should intelligently handle the cache and that the high RAM usage isn't something to be concerned about. There are various lines of code (see my post here) one can run via SSH to clean out the cache if one is concerned about the RAM hitting the high 90's after writing files to the USB device. Example line of code to run via SSH on the router:

sync && echo 3 > /proc/sys/vm/drop_caches

 

[Tech9]

I have a 2GB SWAP file setup

You can see the usage of this swap file in Tools. If the router reaches OOM condition this dead slow swap on USB won't help.

 

[ColinTaylor]

@JGMan As alluded to in the previous post this is really nothing to do with Transmission. It is the normal memory management mechanism of Linux when writing to storage devices. So there's nothing to fix. You could periodically clear the system cache but then you would be negatively impacting the performance of the storage device.

 

[JGMan]

Thanks for the advice and guidance, all!

Considering I am now trusting that the RAM will effectively manage itself, how do you think I should approach the “cache-size-mb”, “peer-global-limit” and “peer-limit-per-torrent” settings?

Considering it will likely always be at 97%, do these settings really matter? Or should I calculate the numbers to use, based on 400MB free RAM?

 

[postoronnim-v]

(40%) free RAM before downloading a torrent. Once the torrent starts, it eats the RAM up until 97% utilized.

Same problem. When starting transmission, I observe a memory leak. Even if all distributions are stopped, the memory “leaks”. It ends with the router freezing. You can only reboot via the power button. Are there any solutions? This is weird. I previously used an RT-N56U which could last for over 5 months without rebooting. And now I have an RT-AX68U, with the same tasks it freezes every week.