Whu does Ubuntu use so much resources

[lammert-nijhof]

DID YOU USE THE ZFS EXPERIMENTAL INSTALL? That would explain your memory usage, since ZFS reserves a large part of the free memory as cache and that is counted as used memory. It will free that memory again, if you load more programs, but that makes your system somewhat slower. I use ZFS since March 2018 and I boot from ZFS since Jan 2019. I maximize the cache size to 20-25% of my total memory in /sys/module/zfs/parameters/zfs_arc_max. By default it contains 0, no limit, but you can specify there a large number, specifying the maximum size of the cache in BYTES.

You can type: "arc_summary" to get a lists of all ZFS sizes and performances. It is a huge list, but in the first 10 lines you can see the cache (L1ARC) size. Somewhat further on it will give you even the cache hit rates.

[kansasnoob]

That seems unusually high even for the out-of-box GNOME 3 DE, although I do typically see high CPU usage the first few minutes after boot while unattended upgrades runs in the background. Even with Firefox open I typically only see RAM usage around 1.5 to 2 GB unless I have some very heavy web content loading. Of course it depends greatly on where I'm looking because some stats show cached RAM usage as actually USED RAM, but cached RAM is better thought of as reserved - not actually used because it'll be reallocated as needed as the priority of processes changes.

[kansasnoob]

DID YOU USE THE ZFS EXPERIMENTAL INSTALL? That would explain your memory usage, since ZFS reserves a large part of the free memory as cache and that is counted as used memory. It will free that memory again, if you load more programs, but that makes your system somewhat slower. I use ZFS since March 2018 and I boot from ZFS since Jan 2019. I maximize the cache size to 20-25% of my total memory in /sys/module/zfs/parameters/zfs_arc_max. By default it contains 0, no limit, but you can specify there a large number, specifying the maximum size of the cache in BYTES.

You can type: "arc_summary" to get a lists of all ZFS sizes and performances. It is a huge list, but in the first 10 lines you can see the cache (L1ARC) size. Somewhat further on it will give you even the cache hit rates.

Good point. I hadn't thought of that. It should be noted that the release notes clearly state Support for ZFS as the root filesystem is added as an experimental feature in 19.10. Intentional emphasis on experimental.

[bernard010]

My Ubuntu 19.10 Gnome is only using 1.3 GB of memory out of 8 GB.
That is while reading and typing on this forum + Live streaming Video/Music in the background.
Kernel 5.3.0-23
Something to remember how much you have going on the O.S. accounts for its Resources. True?