What happens when freenas runs out of memory?

[ShimadaRiku]

Freenas ZFS wants at least 8GB to be happy. I have 16GB installed.

What happens when memory runs low because my jails started using too much?

 

[Bidule0hm]

Swap space is used and if it's not enough then the server crashes.

But what I see on the screenshot is normal, ZFS use most of the RAM.

 

[ShimadaRiku]

ZFS happily will eat all the ram it is given, but will it know to share some of it when other jail/process need them?

 

[pirateghost]

ZFS happily will eat all the ram it is given, but will it know to share some of it when other jail/process need them?

Yes

 

[DifferentStrokes]

What happens when memory runs low because my jails started using too much?

View attachment 9054

A black hole opens in the galaxy and all your data is sucked in. :D

 

[ShimadaRiku]

A black hole opens in the galaxy and all your data is sucked in. :D

So technically my data is traveling faster than speed of light to another point of the universe or dimension?

 

[Bidule0hm]

Yep, ZFS is pure black magic...

 

[DifferentStrokes]

So technically my data is traveling faster than speed of light to another point of the universe or dimension?

Yup or at least it will feel like it is happening that fast if that day comes. ;)

 

[Ericloewe]

So technically my data is traveling faster than speed of light to another point of the universe or dimension?

In your (not-quite-)inertial coordinate system, it'll appear to be moving rather slowly, so don't worry about physics - the universe will not be destroyed, even if your pool is. :D

 

[jgreco]

ZFS happily will eat all the ram it is given, but will it know to share some of it when other jail/process need them?

More or less. If you have a truly unmanageable process, as @Bidule0hm suggests, the NAS will start to swap idle processes out to disk. This isn't horrible, but if allowed to continue (such as a fork bomb or memory leak) you can actually run out of swap space too, at which point the system will resort to killing what it thinks might be the problem process. However, if it inadvertently kills your GUI or the middleware or a protocol sharing daemon, your NAS starts to develop some badness.

The default process memory limit in FreeNAS is 32G. You can artificially limit process sizes within a jail by installing some appropriate resource limits, possibly in the jail startup script, so that your jail processes are limited to some much more reasonable number.