I have 2 DELL PERC 6/i controllers on different servers. Only difference is that first is connected to SATA drives and second - to SAS. While there is no problems at all with SAS drive, SATA is not working w/o -T permissive:

Output from controller with SAS drives:

smartctl 5.39 2009-09-22 r2922M [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-9 by Bruce Allen, ​http://smartmontools.sourceforge.net

Creating /dev/megaraid_sas_ioctl_node = 17 Got MegaRAID inquiry.. FUJITSU MAX3073RC D206 Device: FUJITSU MAX3073RC Version: D206 Serial number: DQA3P6700JF9 Device type: disk Transport protocol: SAS Local Time is: Wed Sep 23 17:29:54 2009 EDT Device supports SMART and is Enabled Temperature Warning Disabled or Not Supported SMART Health Status: OK

Current Drive Temperature: 29 C [SKIP]

Output from controller with SATA drives: [root@var-dev smartmontools]# ./smartctl /dev/sda -d megaraid,0 -i -a smartctl 5.39 2009-09-22 r2922 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-9 by Bruce Allen, ​http://smartmontools.sourceforge.net

Creating /dev/megaraid_sas_ioctl_node = 17 Got MegaRAID inquiry.. ATA WDC WD5000AACS-01B01 /dev/sda [megaraid_disk_00] [SAT]: Device open changed type from 'megaraid' to 'sat'

START OF INFORMATION SECTION

Model Family: Western Digital Caviar Green family Device Model: WDC WD5000AACS-00ZUB0 Serial Number: WD-WCASU7381205 Firmware Version: 01.01B01 User Capacity: 500,107,862,016 bytes Device is: In smartctl database [for details use: -P show] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Wed Sep 23 14:31:46 2009 PDT SMART support is: Available - device has SMART capability. SMART support is: Enabled

Rejecting SMART/ATA command to controller Rejecting SMART/ATA command to controller Error SMART Status command failed Please get assistance from ​http://smartmontools.sourceforge.net/ A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.

Trying -T permissive, and, bingo, it works!

smartctl 5.39 2009-09-22 r2922 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-9 by Bruce Allen, ​http://smartmontools.sourceforge.net

Creating /dev/megaraid_sas_ioctl_node = 17 Got MegaRAID inquiry.. ATA WDC WD5000AACS-01B01 /dev/sda [megaraid_disk_00] [SAT]: Device open changed type from 'megaraid' to 'sat'

START OF INFORMATION SECTION

Model Family: Western Digital Caviar Green family Device Model: WDC WD5000AACS-00ZUB0 Serial Number: WD-WCASU7381205 Firmware Version: 01.01B01 User Capacity: 500,107,862,016 bytes Device is: In smartctl database [for details use: -P show] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Wed Sep 23 14:32:31 2009 PDT SMART support is: Available - device has SMART capability. SMART support is: Enabled

Rejecting SMART/ATA command to controller Rejecting SMART/ATA command to controller Error SMART Status command failed Please get assistance from ​http://smartmontools.sourceforge.net/

START OF READ SMART DATA SECTION

SMART overall-health self-assessment test result: PASSED

General SMART Values: Offline data collection status: (0x84) Offline data collection activity

was suspended by an interrupting command from host. Auto Offline Data Collection: Enabled.

Self-test execution status: ( 0) The previous self-test routine completed

without error or no self-test has ever been run.

[SKIP]

smartctl does not use the 9 bit value from the directory properly and instead reads the value 256 as zero

Steps to reproduce: smartctl -l devstat /dev/sdX on any drive that has a directory such as this

0x04       GPL     R/O    256  Device Statistics log

Expected behavior: print device statistics patched version shown

#smartctl -l devstat /dev/sdd
smartctl 6.7 2017-11-06 r4602 [x86_64-linux-4.9.16-gentoo] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

Device Statistics (GP Log 0x04)
Page  Offset Size        Value Flags Description
0x01  =====  =               =  ===  == General Statistics (rev 1) ==
0x01  0x008  4               6  ---  Lifetime Power-On Resets
0x01  0x010  4             913  ---  Power-on Hours
....

Actual Behavior

#smartctl -l devstat /dev/sdd
smartctl 6.7 2017-11-06 r4602 [x86_64-linux-4.9.16-gentoo] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

Device Statistics (GP/SMART Log 0x04) not supported

fix: included patch, enable already existing code to parse >8bit values in GetNumLogSectors? when reading gplog devstat logs.

The LifeTime(hours) column in the smartctl -l selftest output would be much more useful if the output also displayed the current value for this, allowing the user to see how long ago the tests actually ran. Instead, currently one has to look at the output of e.g. smartctl -a to check the power on hours manually before that column is of any use other than as a relative time between different tests in the log.