Swap since dragonfish upgrade

TrueNAS General
1

Hi there,

First i apologize for my bad english, i’m french and in France we are shit about english !

So i’m coming from Core then Cobia and now Dragonfish. Migration from Core to Cobia was fine, i managed to switch to k3s for my apps greatly. Everything was fine until i upgrade to dragonfish.

Since Dragonfish, ZFS cache eat all of RAM ( it seem it’s ok until RAM are released when needed by the system ). But in fact, the system is now going to swap a lot as if ZFS cache do not release memory as needed by the system …
WebUI start to be realy unresponsive, this is realy anoying.

Am i alone to seeing this ? Can we revert back to 50% RAM for ZFS cache ?

[Album] imgur.com
[Album] imgur.com
2

Founded the trick, thanks to community :

echo 8589000000 >> /sys/module/zfs/parameters/zfs_arc_max

For 8 GB of cache max.

Add this to “System settings”’ → “Advanced” → “Init script” then add this command at boot. No more swap now !

3

I ran into a similar issue after the Dragonfish upgrade. My system also started swapping a lot, even though there was still plenty of ARC memory in use. It looked like the ARC wasn’t releasing RAM quickly enough when the system needed it.

Also, I had to laugh a bit at your “in France we are shit about English” comment I get it. I visited France last year and made sure to connect with a local guide through France Private Tours & Local Tour Guides | GoWithGuide because I can’t speak French at all, and yeah, I agree, most people weren’t too comfortable with English either. So no worries, your English here is perfectly understandable!

Curious, have you seen any performance hit since capping the ARC?

Cheers!