memory cache

[MadMan3353]

how long before the System resets its memory cache? out of 24GB i only have 2GB free. all thats running are two apps and im not moving any data. Is there a problem or is this just how truenas works? also is there a way to have a cache drive for the whole truenas system or only for specific pools/Vdevs?

 

[sretalla]

out of 24GB i only have 2GB free

Is there a problem or is this just how truenas works?

Free RAM is wasted money.

ZFS uses RAM to cache blocks until RAM is needed for other things. Don't worry about it.

is there a way to have a cache drive for the whole truenas system or only for specific pools/Vdevs?

Maybe. You probably don't want it though as you're probably not clear on how it would (or would not) benefit you.

What's the performance problem you're trying to solve?

 

[inman.turbo]

instead of scaling back ARC when a vm started which needs some of that memory, scale will just warn you, then crash your system (out of memory)

 

[Ericloewe]

@inman.turbo, I must kindly ask that the discussion not be spread out all over the place.

Scale memory utilization

There was an additional fix related to memory usage here: https://github.com/truenas/middleware/pull/9125 TL;DR you can maybe take a nightly for a spin and see if usage is stabilized. Otherwise wait for 22.02.2. Above fix (unlike charts one) shouldn't be hard to hot-patch. Will this fix...

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