Re: [smartmontools-support] smart Airflow_Temperature_Cel attribute value on Micron RealSSD

[Christian F. <Chr...@t-...>]

Janardhan Molumuri wrote:
> On systems with Micron ReallSSDs, I noticed that 
> Airflow_Temperature_Cel values are not normalized, instead real values 
> causing the smarttools smartctl health check to report failures.
>
> The drive type is present in the smarttools database. Is there a 
> generalized way to run checks so that the reporting is consistent 
> across all the disks [or] we need to intercept these kind of divergences.
>

ATA SMART attributes are vendor specific, so there is no way which works 
with all devices.



> Any ideas on these values? Is there way to identify if the reported 
> value is real vs normalized with smarttools?
>
> From the doc, I read that as long as the value is higher than the 
> threshold its good (i.e. normalized value 100-<realvalue>) otherwise 
> its bad.

Yes, that is existing practice. No, that is not part of the ATA 
standards since ATA-4 (1998).

Newer drives including Micron SSDs support ATA Device Statistics 
(smartctl -l devstat, included in smartctl -x). This is part of recent 
standards and not vendor specific.


>
> #smartctl /dev/bus/0 -d sat+megaraid,9 -H
> smartctl 6.2 2013-07-26 r3841 
> [x86_64-linux-2.6.32-431.17.1.el6.x86_64] (local build)
> Copyright (C) 2002-13, Bruce Allen, Christian Franke, 
> www.smartmontools.org <http://www.smartmontools.org>
>
> === START OF READ SMART DATA SECTION ===
> SMART overall-health self-assessment test result: FAILED!
> Drive failure expected in less than 24 hours. SAVE ALL DATA.
> Failed Attributes:
> ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE     
>  UPDATED  WHEN_FAILED RAW_VALUE
> 190 Airflow_Temperature_Cel 0x0023   019   033   069  Pre-fail  Always 
>   FAILING_NOW 19 (Min/Max 17/33)
>

None of the specs or previous sample outputs from Micron RealSSDs 
include attribute 190.

Please provide output of

   smartctl -r ioctl,2 -i -H -d sat+megaraid,9 /dev/bus/0

(as an attachment)

I want to make sure that drive's SMART STATUS command actually returns 
FAILED.
In this case this is probably a drive firmware bug.

Thanks,
Christian