Constant Pool activity during idle (zfs_txg_timeout)

[Kampix]

Hello,

I switched from OMV to TrueNAS some time ago and noticed quite quickly that my HDD makes noises every few seconds.
So I spent some time searching for the cause and came across to the "variable" "zfs_txt_timeout".
By default there is a time of 5 seconds in there, which also matches the time of the accesses to the HDD. If I now change this time, the cycle of the accesses and thus the noise of the HDD also changes.

Since the NAS is located in my living room, I would like to avoid these noises and preferably turn them off completely when the NAS is in idle. Since I do not know exactly what this variable is for, I would like to know from you whether it can be changed without problems, or whether these accesses can be turned off completely. I am open for all possible suggestions.

 

[NugentS]

The system dataset, by default on the first Pool you create, is probably the cause. Move that to an SSD. Don't mess with zfs_txt_timeout
As you didn't post your hardware (as per forum rules) there isn't much more I can suggest

 

[Kampix]

The system dataset, by default on the first Pool you create, is probably the cause. Move that to an SSD. Don't mess with zfs_txt_timeout
As you didn't post your hardware (as per forum rules) there isn't much more I can suggest

Thanks for the quick reply.
Sorry, I had actually just forgotten with the system, so here again the data to my system:

Mainboard: ASRock Z490 Phantom Gaming ITX/TB3 ITX
CPU: Intel(R) Pentium(R) Gold G6405 CPU @ 4.10GHz
RAM: Crucial CL22 3200 MHz DDR4 16GB
Boot SSD: 128GB Patriot P300 M.2
HDD: Seagate IronWolf 4TB
System: TrueNAS-SCALE-22.12.3.3

Regarding the system dataset, I initially also thought that the problem could be related to this, however, I had already pushed this to the boot SSD and the problem is still present. Every few Seconds (in the cycle of "zfs_txg_timeout") the HDD LED flashes and the hard disk makes a short noise.

 

[NugentS]

Then you would appear to have something writing to the HDD's

Try zpool iostat -v 1 to watch what happens

 

[Kampix]

Thanks for your help.

I found out, that while the app pool is set to my HDD, the described "problems" appear.
So I changed the App Pool to a SSD an the Noises are gone.

 

[NugentS]

That would make sense - the ix-applications dataset seems to be busy by design

 

[dreg35]

Thanks for your help.

I found out, that while the app pool is set to my HDD, the described "problems" appear.
So I changed the App Pool to a SSD an the Noises are gone.

Quick question, how did you change your App Pool?