High CPU

[sboutros]

Hello, I've been a FreeNAS user since 9.x and it's been really stable for me till I upgraded to 10.x
I know I am not using very powerful hardware (8GB (non-ECC) with Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz) but I am surprised how 10.x and 11.x have gotten sluggish at times to the point that the box is unusable.

The primary CPU hogging suspects are kernel and python related processes (middlewared) when I run top.
I have one plugin (Emby) and it is OFF at the moment.
I have even turned off collectd to reduce load on the system.

Questions:
What does middlewared do?
How can I further dig into kernels CPU use?
Any tips for maximizing performance on older hardware?


root@freenas:~ # ps -ax | grep "[p]ython"
218 - S 107:49.30 python3.6: middlewared (python3.6)
2814 - I 32:44.02 python: alertd (python3.6)
4726 - SJ 1:28.98 /usr/pbi/emby-amd64/bin/python2.7 /usr/pbi/emby-amd64/control.py start 192.168.1.248 12352
5694 v0 Is+ 0:04.27 /usr/local/bin/python /etc/netcli (python3.6)

 

[Chris Moore]

Any tips for maximizing performance on older hardware?

Can you post more details on just exactly what hardware you have including drive controllers and number of drives?
It would also be helpful to know exactly what version of FreeNAS you are using.
Is there a reason you can't upgrade the RAM because 8GB if the bare minimum?
You will not get good performance when you are using the bare minimum hardware.

What does middlewared do?

Middleware is what interfaces between the GUI and the operating system.

 

[sboutros]

Sorry about that. It is a basic Dell Optiplex 760

Drive controller = on-board/motherboard.
3 internal 2TB disks.
OS on USB thumb drive.
1 USB attached external 2TB disk.

FreeNAS-11.1-U2
8GB RAM - I can upgrade the RAM, just not sure that is the limiting factor at this point.

 

[Chris Moore]

1 USB attached external 2TB disk.

Is this part of your storage pool?
How much swap is being utilized?
Can you post the graph from the GUI?
Looks like this:

 

[Chris Moore]

Sorry about that. It is a basic Dell Optiplex 760

That system (from the specs you linked to) maxes out at 8GB of RAM and it is DDR2 memory.
That is very much an older, slower type of system that you should be seriously looking at replacing.
That is not to say you need something shiny and new, but something newer than that. I had a Dell Precision T3400 (similar vintage) as my first FreeNAS back around 2011, and I understand that it is hard to let go of those older systems. I still have some of them around my house running Linux, slowly. This is just a bit too old to keep up with some of the newer elements of FreeNAS.

 

[MrToddsFriends]

Just an idea: Set up a cron job with Stux' pagein script, for example every n hours with typically 1 ≤ n ≤ 6. You will be notified by email if the script has had something to do (i.e. swap was used before running the script).
https://forums.freenas.org/index.ph...ny-used-swap-to-prevent-kernel-crashes.46206/

Background: There was some change in FreeNAS behavior from 9.3 to 9.10 that led to increased swap usage. All following FreeNAS versions seem to have inherited this increased swap usage.

If periodically running the pagein script reveals a correlation between "being sluggish at times" and "swap usage" you can go on with looking for a workaround that is suitable for you, maybe either by using the vm.v_free_target and vfs.zfs.arc_free_target tunables
https://forums.freenas.org/index.php?threads/swap-with-9-10.42749/page-5
or by using the vfs.zfs.arc_max tunable
https://forums.freenas.org/index.php?threads/vfs-zfs-arc_max-has-immediate-effect.55768/

That having said, your system is clearly not well suited to act as ZFS NAS. It was reported from many sides that a FSB is a severe obstacle for good ZFS performance.