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#46903 - 11/18/17 01:52 AM S.M.A.R.T. testing and SSDs
artie505 Online


Registered: 08/04/09
Originally Posted By: joemikeb
If you have 50 or so minutes to spare you might find this video presentation on HFS+ and APFS by OWC's engineering manager interesting. Among other things it covers your specific question and the differences in what happens between HFS+ and APFS.

I finally steeled myself and watched your linked video, and as was the case with most of my college lectures I've got somewhere between little and no idea of what I heard. It was, for the most part, just plain technical beyond my ability to comprehend, not to mention that it's having been directed at an audience with infinitely more technical knowledge than I've got resulted in much of even the comprehensible stuff having whizzed by before I could digest it.

In the end, though, while I've got great faith in your glowing reviews of APFS, I learned enough to induce me to follow Urquhart's lead and stick with HFS+, in my case until the extreme lack of documentation, at the very least, is resolved, or, alternatively, until I've got no other option.

Many thanks for the link; both what I learned and what I merely picked up on will be useful down the road.

Question: S.M.A.R.T. testing applies to SSDs as well as HDDs, but the Smart Alec software that was mentioned, right down to the images in its documentation, seem directed specifically at HDDs.

Is it as/at all pertinent to SSDs?


Edited by joemikeb (11/19/17 09:41 AM)

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#46908 - 11/18/17 11:11 AM Re: S.M.A.R.T. and SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
I downloaded Smart Alec and to my great surprise discovered that on my 13" MacBook Pro Touch bar S.M.A.R.T Is NOT supported on the SSD. USB and Firewire attached drives do not support S.M.A.R.T. and although it is supported on Thunderbolt attached drives, because my TB attached drives are part of a SoftRAID (now an OWC owned product) array, Smart Alec won't read them either. So, on my system Smart Alec is 100% useless. tongue

YMMV


Edited by joemikeb (11/19/17 09:42 AM)
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#46912 - 11/18/17 02:35 PM Re: S.M.A.R.T. and SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
I intend to try SMART Alec and will report back.

Originally Posted By: joemikeb
USB and Firewire attached drives do not support S.M.A.R.T.....

Originally Posted By: SMART Alec Disk Monitoring
SMART ALEC FOR USB & FIREWIRE

Introducing SMART over USB, a brand new feature available with SMART Alec that will enable failure prediction features to work on your USB and FireWire Disks.

SMART over USB will be available as a paid upgrade ($9.99) once SMART Alec is officially launched in Summer 2017. [ tongue ]

If you'd like to try it out now, become a beta tester! Application form available here. (Smiley added)

Does that contradict you, do you contradict it, or is it a newly added feature?

Mods: Should this and the previous post be the beginnings of a new thread?

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#46915 - 11/18/17 10:33 PM Re: S.M.A.R.T. and SSDs [Re: artie505]
artie505 Online


Registered: 08/04/09
Originally Posted By: artie505
I intend to try SMART Alec and will report back.

I had no better luck than you did; SMART Alec was unable to see the SSD in my MBP.

I didn't even bother to try it with my external SSD.

Looks like it's for HDDs only?

More: I emailed them and will post when they reply.

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#46923 - 11/19/17 09:32 AM Re: S.M.A.R.T. and SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Originally Posted By: artie505
Originally Posted By: artie505
I intend to try SMART Alec and will report back.

I had no better luck than you did; SMART Alec was unable to see the SSD in my MBP.

I also tried Disk Utility, a just released Drive Genius beta that is APFS and High Sierra compatible, the latest release of Tech Tool Pro. Drive Genius and Tech Tool Pro don't even show the internal SSD on my MBP when the S.M.A.R.T. test is selected. If you select the SSD in Disk Utility it reports "S.M.A.R.T. status: Not Supported" as seen here. There are S.M.A.R.T. parameters that would appear to be applicable to SSDs, but Apple is not going to let us see them.

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#46924 - 11/19/17 09:43 AM Re: S.M.A.R.T. and SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
I'm seeing this in Sierra, so there's definitely some aspect of S.M.A.R.T. that applies to SSDs.

Also, EtreCheck generates a S.M.A.R.T. report...not that I can make heads or tails of it.

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#46925 - 11/19/17 10:38 AM Re: S.M.A.R.T. and SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
I just tried Etrecheck and on my MBP running High Sierra (MacOS 10.12.2 beta 5) this is all I got on the SSD — no S.M.A.R.T. results.

As to reading the S.M.A.R.T. reports in Etrecheck (or Tech Tool Pro) the only part of the report to be concerned with is this. and particularly the "failed" column. There are far more parameters defined than you see but the drive manufacturer determines which of the available factors the drive will collect and report. They also determine the pass/fail level for each parameter and that is almost always set to a high — very high — tolerance. It is possible to have one or two parameters reporting "failed" with the aggregate pass/fail score still being "pass". So apps such as Disk Utility that report only the aggregate score can indicate a failing drive as "verified or pass". Smart Alec apparently has a much lower "verified" tolerance and I concur in its estimate.

NOTE: S.M.A.R.T. is strictly hardware related and there is no consideration of how the drive is formatted or if there are format errors.
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#46947 - 11/20/17 11:16 PM Re: S.M.A.R.T. and SSDs [Re: joemikeb]
artie505 Online


Registered: 08/04/09
Originally Posted By: joemikeb
I just tried Etrecheck and on my MBP running High Sierra (MacOS 10.12.2 beta 5) this is all I got on the SSD — no S.M.A.R.T. results. (That's 10.13.2 beta 5, I assume?)

Something has changed somewhere, because EtreCheck 3.4.6 returns this in macOS 10.12.6 on my MBP.

And "Show SMART report" returns this...

Code:
smartctl 6.5 2016-05-07 r4318 [Darwin 16.7.0 x86_64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Apple SD/SM/TS...E/F SSDs
Device Model:     APPLE SSD SM0512G
Serial Number:    S29ANYAH406432
LU WWN Device Id: 5 002538 900000000
Firmware Version: BXW1SA0Q
User Capacity:    500,277,790,720 bytes [500 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 4c
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Mon Nov 20 10:00:17 2017 EST
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

General SMART Values:
Offline data collection status:  (0x00)	Offline data collection activity
					was never started.
					Auto Offline Data Collection: Disabled.
Self-test execution status:      (   0)	The previous self-test routine completed
					without error or no self-test has ever 
					been run.
Total time to complete Offline 
data collection: 		(    0) seconds.
Offline data collection
capabilities: 			 (0x53) SMART execute Offline immediate.
					Auto Offline data collection on/off support.
					Suspend Offline collection upon new
					command.
					No Offline surface scan supported.
					Self-test supported.
					No Conveyance Self-test supported.
					Selective Self-test supported.
SMART capabilities:            (0x0003)	Saves SMART data before entering
					power-saving mode.
					Supports SMART auto save timer.
Error logging capability:        (0x01)	Error logging supported.
					General Purpose Logging supported.
Short self-test routine 
recommended polling time: 	 (   2) minutes.
Extended self-test routine
recommended polling time: 	 (  10) minutes.

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
  1 Raw_Read_Error_Rate     0x001a   200   200   000    Old_age   Always       -       0
  5 Reallocated_Sector_Ct   0x0033   100   100   000    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   097   097   000    Old_age   Always       -       13127
 12 Power_Cycle_Count       0x0032   099   099   000    Old_age   Always       -       683
169 Unknown_Attribute       0x0013   242   242   010    Pre-fail  Always       -       3543524181888
173 Wear_Leveling_Count     0x0032   198   198   100    Old_age   Always       -       21480144933
174 Host_Reads_MiB          0x0022   099   099   000    Old_age   Always       -       9129718
175 Host_Writes_MiB         0x0022   099   099   000    Old_age   Always       -       7606330
192 Power-Off_Retract_Count 0x0012   099   099   000    Old_age   Always       -       20
194 Temperature_Celsius     0x0022   064   019   000    Old_age   Always       -       36 (Min/Max 23/82)
197 Current_Pending_Sector  0x0022   100   100   000    Old_age   Always       -       0
199 UDMA_CRC_Error_Count    0x001a   200   200   000    Old_age   Always       -       0

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
No self-tests have been logged.  [To run self-tests, use: smartctl -t]

Warning! SMART Selective Self-Test Log Structure error: invalid SMART checksum.
SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
  255        0    65535  Read_scanning was never started
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.

I was going to ask what it all means and which parts matter, but I think you've already answered my questions.

Originally Posted By: joemikeb
Smart Alec apparently has a much lower "verified" tolerance and I concur in its estimate.

How did you determine that if Smart Alec couldn't see your SSD?
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#46970 - 11/21/17 11:17 AM Re: S.M.A.R.T. and SSDs [Re: artie505]
joemikeb Online

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
The only possible explanations I have for the difference in your results and mine with Etrecheck, and confirmed by Disk Utility, TechTool Pro, Tinkertool System, and Drive Genius are:
  1. I am using a different version of MacOS (10.13.2 beta 4)
  2. My SSD is formatted APFS (but S.M.A.R.T. is purely hardware and the format should not effect the hardware)
  3. I have a different model MacBook Pro
  4. I am not holding my mouth right when I run Etrecheck or any of the other utilities

Originally Posted By: artie505
Originally Posted By: joemikeb
Smart Alec apparently has a much lower "verified" tolerance and I concur in its estimate.

How did you determine that if Smart Alec couldn't see your SSD?

I base that on
  • a previous version of Smart Alec that I beta tested on my Mac mini
  • Assumed from comments made by Smart Alec developers (I know — assumed)
  • Knowledge of S.M.A.R.T. test limitations reported many years ago by Google Labs
  • Years of experience seeing all the various parameters via TechTool Pro
  • Two occassions of drives reporting "verified" in Disk Utility while TechTool Pro was showing multiple failed S.M.A.R.T. parameters when the drive had actually failed
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