Re: smart Airflow_Temperature_Cel attribute value on Micron RealSSD

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


------------------------------------------------------------------------------
HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions
Find What Matters Most in Your Big Data with HPCC Systems
Open Source. Fast. Scalable. Simple. Ideal for Dirty Data.
Leverages Graph Analysis for Fast Processing & Easy Data Exploration
http://p.sf.net/sfu/hpccsystems