Apple TS0256F shows spurious FAILING_NOW results

[Chris Ferebee]

I have a 256 GB SSD in my 2014 11" MacBook Air, OS X 10.11.0. I believe the TS0256F is manufactured by Toshiba, while many MacBooks use an SM0256F manufactured by Samsung.

Almost all parameters are listed as FAILING_NOW, but the SSD appears to function normally in every way. For example, when the MacBook is idle, temperature is reported as 32 (see below), and with the SSD under heavy continuous write load the temperature parameter will go up to 82. Read and write speeds are as expected, around 550/450 MB/s.

I understand that attribute 173 (Wear_Leveling_Count) starts at 200 and counts down, triggering an error when it reaches 100. It's currently at 197, which I take as confirmation that the drive has not been overused.

Is this just a cosmetic bug?

# smartctl -a /dev/disk0
smartctl 6.4 2015-06-04 r4109 [x86_64-apple-darwin15.0.0] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Apple SD/SM/TS...E/F SSDs
Device Model:     APPLE SSD TS0256F
Serial Number:    34GSxxxxxxxx
Firmware Version: 109R0219
User Capacity:    251,000,193,024 bytes [251 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    Solid State Device
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS T13/1699-D revision 6
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: >6.0 Gb/s (4))
Local Time is:    Sat Oct 10 16:13:56 2015 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
See vendor-specific Attribute list for marginal Attributes.

General SMART Values:
Offline data collection status:  (0x00)	Offline data collection activity
					was never started.
					Auto Offline Data Collection: Disabled.
Total time to complete Offline 
data collection: 		(    0) seconds.
Offline data collection
capabilities: 			 (0x00) 	Offline data collection not supported.
SMART capabilities:            (0x0003)	Saves SMART data before entering
					power-saving mode.
					Supports SMART auto save timer.
Error logging capability:        (0x00)	Error logging NOT supported.
					No General Purpose Logging support.

SMART Attributes Data Structure revision number: 40
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x0000   000   100   100    Old_age   Offline  FAILING_NOW 0
  5 Reallocated_Sector_Ct   0x0000   000   100   100    Old_age   Offline  FAILING_NOW 0
  9 Power_On_Hours          0x0000   000   100   100    Old_age   Offline  FAILING_NOW 144
 12 Power_Cycle_Count       0x0000   000   100   100    Old_age   Offline  FAILING_NOW 3360
169 Unknown_Attribute       0x0008   100   100   010    Old_age   Offline      -       1851873300992
173 Wear_Leveling_Count     0x0010   197   197   100    Old_age   Offline      -       77315768372
192 Power-Off_Retract_Count 0x0000   000   100   100    Old_age   Offline  FAILING_NOW 20
194 Temperature_Celsius     0x0000   068   100   100    Old_age   Offline  FAILING_NOW 32 (Min/Max 18/83)
197 Current_Pending_Sector  0x0000   100   100   100    Old_age   Offline  FAILING_NOW 0
199 UDMA_CRC_Error_Count    0x0000   000   100   100    Old_age   Offline  FAILING_NOW 0
174 Host_Reads_MiB          0x0000   015   100   100    Old_age   Offline  FAILING_NOW 24191827
175 Host_Writes_MiB         0x0000   021   100   100    Old_age   Offline  FAILING_NOW 3980335
151 Unknown_Attribute       0x0086   000   000   ---    Old_age   Always       -       0

SMART Error Log not supported

SMART Self-test Log not supported

Selective Self-tests/Logging not supported

[Alex Samorukov]

Most likely it is a buggy firmware in the listed SSD. I would recommend to try also run smartctl from Linux (using LiveUSB) to see if it will differ, but probably - it wont. Also with recent smartmontools you can use -l devstat to see statistical data from the stanarized log tables.

[Alex Samorukov]

if found discussion about this issue in this thread: ​http://sourceforge.net/p/smartmontools/mailman/message/32646633/. So it seems to be fw bug of this specific drive, i am closing this report. So yes, it is a cosmetic bug.