/sbin/zsysd is eating all RAM and swap on Ubuntu 20.04 with ZFS

[Flaiming]

I have an issue with memory consumption of /sbin/zsysd - it is slowly eating my RAM (32GB) and then even swap so after 2 days from restart I have none of it left, see attached image.

I tried to change zfs_arc_max value to 8GB according to https://askubuntu.com/a/1290387/970404, but did not helped at all.

[Flaiming (vojtech-o)]

ps auxw > ps.txt

[Flaiming (vojtech-o)]

free -m > free.txt

[Miles Zhao (mingzym)]

On 22.04, I saw similar issue after a few apt upgrade, which trigger zsys service etc.
the zsysd will consume much more memory than it should do. and no response when apt requesting.
here is a typical result:

root@zymElite:~# apt-get update;apt-get dist-upgrade
Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:2 http://packages.microsoft.com/repos/edge stable InRelease
Hit:3 http://archive.ubuntu.com/ubuntu jammy InRelease
Get:4 http://archive.ubuntu.com/ubuntu jammy-updates InRelease [109 kB]
Hit:5 https://ppa.launchpadcontent.net/agornostal/ulauncher/ubuntu jammy InRelease
Get:6 http://archive.ubuntu.com/ubuntu jammy-backports InRelease [99.8 kB]
Get:7 http://archive.ubuntu.com/ubuntu jammy-security InRelease [110 kB]
Get:8 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages [277 kB]
Get:9 http://archive.ubuntu.com/ubuntu jammy-updates/main i386 Packages [124 kB]
Get:10 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 DEP-11 Metadata [73.4 kB]
Get:11 http://archive.ubuntu.com/ubuntu jammy-updates/universe i386 Packages [46.3 kB]
Get:12 http://archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages [116 kB]
Get:13 http://archive.ubuntu.com/ubuntu jammy-updates/universe Translation-en [40.1 kB]
Get:14 http://archive.ubuntu.com/ubuntu jammy-updates/universe amd64 DEP-11 Metadata [92.0 kB]
Get:15 http://archive.ubuntu.com/ubuntu jammy-updates/universe amd64 c-n-f Metadata [2,344 B]
Get:16 http://archive.ubuntu.com/ubuntu jammy-backports/universe amd64 DEP-11 Metadata [1,192 B]
Get:17 http://archive.ubuntu.com/ubuntu jammy-security/main amd64 DEP-11 Metadata [11.4 kB]
Get:18 http://archive.ubuntu.com/ubuntu jammy-security/universe amd64 c-n-f Metadata [1,128 B]
Fetched 1,104 kB in 5s (229 kB/s)
Reading package lists... Done
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  deja-dup
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 298 kB of archives.
After this operation, 8,192 B of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 deja-dup amd64 42.9-1ubuntu3 [298 kB]
Fetched 298 kB in 2s (149 kB/s)
ERROR Service took too long to respond. Disconnecting client.
(Reading database ... 288053 files and directories currently installed.)
Preparing to unpack .../deja-dup_42.9-1ubuntu3_amd64.deb ...
Unpacking deja-dup (42.9-1ubuntu3) over (42.9-1ubuntu2) ...
Setting up deja-dup (42.9-1ubuntu3) ...
Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu3) ...
Processing triggers for libglib2.0-0:amd64 (2.72.1-1) ...
Processing triggers for libglib2.0-0:i386 (2.72.1-1) ...
Processing triggers for man-db (2.10.2-1) ...
Processing triggers for mailcap (3.70+nmu1ubuntu1) ...
ER...