I have a script that uses smartctl to read the disks temperature and adjust the case fan accordingly.
However, after upgrading to 25.10 the script stopped working.
while troubleshooting i noticed that if i used the command
sudo smartctl -A /dev/sdb
I would get a response similar to this
Basically, SMART is disabled for all the disks except for the Boot drive. To enable it, i have to issue the following command for each drive
sudo smartctl -s on /dev/sdb
AND i have to remember to do this after every boot.
Have any of you noticed this?
How can i enable SMART on my system so i would not need to do it myself manually every time?
I don’t know why it’s disabled for you and hopefully someone does, but if you absolutely must run a command after each boot then you can automate that. I think you can add it as a post-init command under System→Advanced→Init/Shutdown Scripts.
A measure of last resort.
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Thanks for the response.
I guess i could do a post-init script if everything else fails.
I was really hoping i was missing a configuration somewhere. Using a post-init feels forced.
I’m also finding this same issue, SMART tests are disabled and Scrutiny reports all drives except boot drive as failed. Have added the post init script to re-enable, but would love to know why this happens
Maybe check out the TrueNAS Tech Talk about SMART? It also mentions Scrutiny
@ijamigo would you be willing to share your post init script?
I’m guessing it’d be:
but repeated for each drive that you’d want SMART enabled on.
Oddly I do not have the same issue & I seem to still have smart enabled on each drive.
yeah, i figured as much. I was hoping there was a more elegant, single line of code way to do this.
Having 4 entries to do the same thing (one for each drive) seems a bit silly to me.
It is interesting that you are not experiencing this behavior.
LarsR
August 14, 2026, 1:19pm
9
Same for me. Smart enabled on all devices by default…
Well, then it must be something on my system then.
and, are you running something else such as the multi-report script maybe?
LarsR
August 14, 2026, 1:32pm
11
Updated to 25.10.6 yesterday. But the system is running with the same disks since the first release of scale in 2022 and got updated to each version of scale when they became available.
Maybe because we upgraded & had the smart chrons import over from previous versions? I’m too lazy to try a clean install to see if this a recent change.
You also don’t need to have x amount of entries as post-init scripts per drive. You could just have single entry & have it run a script. Toss in a #!/bin/bash followed by the smart -s on per drive into a .sh file, have the post-init point at the script.
If you’re actually good at linux I’m sure you could make something that actually checks what drive letters are present & runs the command for each; would likely be of use if you have a lot of drives or make a bunch of changes to your system semi-frequently. This is beyond my skill (ie: time I’m willing to invest at the moment).
LarsR
August 14, 2026, 2:09pm
13
Going from @ragametal signature his systems were also set up when smart was still around in the gui.
1 Like
I upgraded over time, instead of doing fresh install. During the upgrade, the cron jobs for the smart tests were also created automatically for me during the upgrade.
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@Fleshmauler , at this point, your suggestion of writing a script sounds like the best choice. Thanks for the input.
1 Like
LarsR
August 14, 2026, 7:33pm
16
Ok did a test setup with an old workstation pc i had laying around and a pair old intel ssd.
Welcome to TrueNAS
Last login: Fri Aug 14 12:30:27 PDT 2026 on pts/0
truenas_admin@truenas[~]$ sudo smartctl -A /dev/sda
[sudo] password for truenas_admin:
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.12.99-production+truenas] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
5 Reallocated_Sector_Ct 0x0032 099 099 000 Old_age Always - 1
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 72843
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 61
170 Available_Reservd_Space 0x0033 099 099 010 Pre-fail Always - 0
171 Program_Fail_Count 0x0032 100 100 000 Old_age Always - 0
172 Erase_Fail_Count 0x0032 100 100 000 Old_age Always - 0
174 Unsafe_Shutdown_Count 0x0032 100 100 000 Old_age Always - 36
175 Power_Loss_Cap_Test 0x0033 100 100 010 Pre-fail Always - 15070 (485 4)
183 SATA_Downshift_Count 0x0032 100 100 000 Old_age Always - 0
184 End-to-End_Error_Count 0x0033 100 100 090 Pre-fail Always - 0
187 Uncorrectable_Error_Cnt 0x0032 100 100 000 Old_age Always - 0
190 Case_Temperature 0x0022 071 071 000 Old_age Always - 29 (Min/Max 29/29)
192 Unsafe_Shutdown_Count 0x0032 100 100 000 Old_age Always - 36
194 Drive_Temperature 0x0022 100 100 000 Old_age Always - 29
197 Pending_Sector_Count 0x0012 100 100 000 Old_age Always - 0
199 CRC_Error_Count 0x003e 100 100 000 Old_age Always - 0
225 Host_Writes_32MiB 0x0032 100 100 000 Old_age Always - 2501266
226 Workld_Media_Wear_Indic 0x0032 100 100 000 Old_age Always - 102400
227 Workld_Host_Reads_Perc 0x0032 100 100 000 Old_age Always - 0
228 Workload_Minutes 0x0032 100 100 000 Old_age Always - 3809066376
232 Available_Reservd_Space 0x0033 099 099 010 Pre-fail Always - 0
233 Media_Wearout_Indicator 0x0032 093 093 000 Old_age Always - 0
234 Thermal_Throttle_Status 0x0032 100 100 000 Old_age Always - 0/0
241 Host_Writes_32MiB 0x0032 100 100 000 Old_age Always - 2501266
242 Host_Reads_32MiB 0x0032 100 100 000 Old_age Always - 14219694
243 NAND_Writes_32MiB 0x0032 100 100 000 Old_age Always - 11444684
truenas_admin@truenas[~]$ sudo smartctl -A /dev/sdb
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.12.99-production+truenas] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
5 Reallocated_Sector_Ct 0x0032 100 100 000 Old_age Always - 4
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 72844
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 60
170 Available_Reservd_Space 0x0033 099 099 010 Pre-fail Always - 0
171 Program_Fail_Count 0x0032 100 100 000 Old_age Always - 7
172 Erase_Fail_Count 0x0032 100 100 000 Old_age Always - 0
174 Unsafe_Shutdown_Count 0x0032 100 100 000 Old_age Always - 35
175 Power_Loss_Cap_Test 0x0033 100 100 010 Pre-fail Always - 14350 (484 6)
183 SATA_Downshift_Count 0x0032 100 100 000 Old_age Always - 0
184 End-to-End_Error_Count 0x0033 100 100 090 Pre-fail Always - 0
187 Uncorrectable_Error_Cnt 0x0032 100 100 000 Old_age Always - 0
190 Case_Temperature 0x0022 072 072 000 Old_age Always - 28 (Min/Max 27/28)
192 Unsafe_Shutdown_Count 0x0032 100 100 000 Old_age Always - 35
194 Drive_Temperature 0x0022 100 100 000 Old_age Always - 28
197 Pending_Sector_Count 0x0012 100 100 000 Old_age Always - 0
199 CRC_Error_Count 0x003e 100 100 000 Old_age Always - 0
225 Host_Writes_32MiB 0x0032 100 100 000 Old_age Always - 2504059
226 Workld_Media_Wear_Indic 0x0032 100 100 000 Old_age Always - 102400
227 Workld_Host_Reads_Perc 0x0032 100 100 000 Old_age Always - 0
228 Workload_Minutes 0x0032 100 100 000 Old_age Always - 3809066383
232 Available_Reservd_Space 0x0033 099 099 010 Pre-fail Always - 0
233 Media_Wearout_Indicator 0x0032 093 093 000 Old_age Always - 0
234 Thermal_Throttle_Status 0x0032 100 100 000 Old_age Always - 0/0
241 Host_Writes_32MiB 0x0032 100 100 000 Old_age Always - 2504059
242 Host_Reads_32MiB 0x0032 100 100 000 Old_age Always - 14223006
243 NAND_Writes_32MiB 0x0032 100 100 000 Old_age Always - 11447497
smart was enabled by default,
1 Like
@LarsR thanks for checking.
I don’t know what is wrong with my system then because the boot drive is the only one that has smart enabled when i restart the TrueNAS server.
I ended up writing a script that enabled smart for all my drives and ran such script as a post-init script.
1 Like
LarsR
August 17, 2026, 2:28pm
18
Did you buy those disks new or were they maybe refurbished? I wonder if they were used in a different environement and had smart disabled intentionally…
I bought all the drives new and never seen this behavior before TrueNAS decided to delete the SMART from the UI.
I installed truenas scale fresh on this system, but i don’t remember when. Then i have been updating it ever since to the latest truenas version.
Farout
August 17, 2026, 3:29pm
20
I just checked. All my SSDs have suddenly smart disabled
2 Likes
. No idea when this happened as I didnt check smart in a while. Must have happened with the update to .5 or .6 or even earlier.