Setting different temperatures for disks in SMART

[cyberjock]

SMART's default WebGUI options allow you to only set a single temperature for difference, informationl, and critical.

Critical will send you an email, and for situations like a FreeNAS Mini this could get annoying. The 4 disks installed in the bays stay cool, but the built-in SATA DOM can often exceed the recommended temperatures. Of course, getting regular alarms because your SATA DOM is over the limit you set for the rotating disks (which should be no higher than 40C) can be a pain. Here's how you fix that....

1. Set the difference, informational, and critical to zero.
2. Go to Storage -> Volumes -> View Disks (applies to 9.2.1.x and the options exist elsewhere for other versions of FreeNAS). Click on the disk you want to control and then click edit.

3. Set the SMART extra options as explained below:

The -W parameter is for temperatures, which are then 3 numbers separated by commas like above. The order is Difference, Informational, and Critical.

In the picture above I set my drive to 0 degrees for Difference and Informational but I will get an email for Critical at 37C.

This obviously will only work for hardware that properly works with SMART. If you are using any kind of RAID controller in an IR mode you likely will not be able to use this anyway.

Note that both the 0,0,0 from the SMART parameters is passed but your extra options will override those values.

So what does this do "behind the scenes"? Here's the output of my /etc/local/smartd.conf file:

Code:

################################################
# smartd.conf generated by /etc/rc.d/ix-smartd
################################################
/dev/ada0 -a -n never -W 0,0,0 -m my@email.com -W 0,0,37
/dev/ada0 -a -n never -W 0,0,0 -m my@email.com -W 0,0,37

 

[aaronadams]

Actually, you just helped uncover an interesting bug! As soon as I edited a disk's SMART setting, the scheduled SMART test for the SSD drive disappeared completely from /etc/local/smartd.conf. Further edits to disk SMART settings and general SMART settings do not cause it to be added back.

I'll file a bug, although I would say this is actually desirable behaviour – it takes care of my false alarms!

 

[cyberjock]

Well that's not good...

I added SMART tests and they are in my smartd.conf. What version are you using?

Can you post a "before and after" so I can better understand what's happening?

 

[aaronadams]

Here you go:

https://bugs.freenas.org/issues/5884

Editing /dev/ada0 made /dev/ada2 disappear from my smartd.conf. 9.2.1.7-RELEASE.

I'm a magician!

 

[cyberjock]

That is just freaky! I tried to fix your problem with the ticket but I can't edit it. I've posted to the devs so one of them can edit it.

 

[aaronadams]

https://bugs.freenas.org/issues/5884#note-5 -> the attachment there is a transcript of a shell session from my twin appliance, where I show that my SSD is included in my smartd.conf; then I run ix-smartd, and show that my SSD is no longer included in my smartd.conf.

So we're either looking at a 9.2.1.6–9.2.1.7 change, intended or not; or we're looking at ix-smartd generating inconsistent smartd.conf files.

 

[cyberjock]

Yikes. I'll be honest, SMART is near and dear to my heart, so I'm going to be following this and looking closely.

 

[aaronadams]

Thankfully the developer is right that there's not too much value in FreeNAS monitoring the drive it's installed on, since it's usually solid state. And since it turns out the monitoring of the FreeNAS Mini's SSD is the bug, looks like I'll eventually get my feature request by proxy!