Alert settings have no effect

[ChrisChros]

Hi,
since I updated to 11.3 RC1 I noticed the informations about the start and stop of a pool-scrub in the Alert window.
In the Alert setting I have chosen the option "NEVER" for scrub start and finish.

So why do I still receive these notifications? Is there any other hidden setting?

What also is al little bit strange to me, I have not setting up a scrub task for this drive because it's an SSD. But it looks like a scrub will be performed.

Thanks for your help.
Chris

 

[HolyK]

Scrub for boot is automatically scheduled by system.

Code:

root@test[/]# cat /etc/crontab | grep boot | grep -v ^#
45      3       *       *       *       root    /usr/local/libexec/nas/scrub -t 7 freenas-boot

 

[ChrisChros]

but is this really necessary on a SSD drive?
And why is this not shown in the cron jobs list in the UI?

 

[HolyK]

Well technically SCRUB is not "necessary" in any case to have operational ZFS. But it is highly recommended in order to capture data corruption in early stages and correct it if possible (or report the failure to sysadmin). HDD or SSD does not matter here as corruption can happen on either of these. Yes it contributes to the "wear level" of the SSD but at these days it shouldn't really matter. For system SSD it is once per 35 days and the "wear level" of one scrub is basically nothing compared to I/O of some notebook running Win10 and used every day for various tasks.
There is similar thread regarding scrub on SSD HERE .

Regarding the cronjob ... You will see only the "user-created" cron task in GUI (meaning these which were created from GUI). There are more "system" cron tasks which are not visible via GUI. Just cat /etc/crontab from CLI you will see these plus the user ones as well.

 

[ChrisChros]

OK thanks for these explanations.
And do you know anything about the other topic, alert setting?

 

[HolyK]

Sadly no as i haven't explored the 11.3 yet. Anyway disabling alerts for scrub in general does not seems to be good idea. If scrub fails for whatever reason you should be notified. I don't know how detailed the alerting config is in 11.3 but only thing i would disable is the "start" and "successful run of scrub with 0 repairs done". Anything else (failure, not-started as per schedule, finished but with repairs done) should be reported to admin.

 

[ChrisChros]

That's what I have disabled. If a scrub ends with a fault I will receive a notification but not when a schrub start and end without a fault.