Topic 'Re: S.M.A.R.T. shows obviously wrong attribute!' in forum 'All Things Unix' - dslreports.com

Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 17:44:27 EDT

KodiacZiller posted : Another reason to use Western Digital, not that the OP had any choice in the matter here.

Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 14:18:02 EDT

koitsu posted : No problem. Knowing how to read SMART stats -- specifically, when to and when not to trust RAW_VALUE -- is incredibly important. Sadly there's no "global standard" for interpreting the results, which is why smartctl has a drive database.

Also, if you plan on using an SSD, you will run into headaches. I document what my experience was like with XP, but the same applies to *IX operating systems. To me, the pain of setting it up (at least on Windows XP -- it's less of a pain on *IX given the low-level nature of partitioning/fs utilities) wasn't worth it. If I ran an *IX OS on my desktop, I'd probably have reinstalled the OS + repartitioned at the proper block boundary and been thrilled. But without a 2nd PC around, this isn't easy to do on XP. :-)
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Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 13:50:51 EDT

OutOfMem posted :

said by koitsu:

There are 3 issues here:

1) Your drive isn't in the internal smartctl database (used for handling SMART attribute tweaks):

Device Model:     FUJITSU MHZ2160BHSerial Number:    K665T8C2CE7NFirmware Version: 00000009User Capacity:    160,041,885,696 bytesDevice is:        Not in smartctl database [for details use: -P showall]

Please get in contact with Bruce Allen and provide him the output you've provided above, and/or any other details he asks for.

2) It doesn't matter what values are shown in the RAW_VALUE column. You cannot look at SMART stats and assume what's returned is literally what's true. Seagate drives, for example, have exceedingly high numbers for SMART attribute 1 and 195, yet the drives are far from going bad.

What you absolutely need to look at under all circumstances is the VALUE compared to THRESH. These are the adjusted threshold values for what will trip a failed SMART health check -- that is to say, the adjusted values are what represent whether or not your drive is in good/bad condition. If you look at attribute 5, you can see that your current VALUE is 100, and the THRESH is set to 24. The WORST column represents the worst value ever seen on the drive, which is 100.

Thus, you can conclude your drive has very few (more than likely, zero!) reallocated sectors.

What you need to understand is that the specification for SMART does not require vendors to store their raw data in a defined format -- they can store whatever values they want there. Seagate is known for encoding some of their raw SMART data in a way which is only known to them. Bruce has figured out a couple of the encoding methods for some of the attributes, but not all of them.

Additionally, your drive has no indication of it ever seeing read or write failures at specific LBAs, indicating sector r/w failures. These would show up in the SMART log, and your SMART log is empty.

I can point you to an older thread here at DSLR where I posted "how" to read SMART attributes, if you'd like to read it.

3) Fujitsu has a very long history of "abusing" SMART. You can read the smartmontools FAQ page and documentation for further evidence of this.

And for sake of argument: we use Fujitsu SCSI drives (both 37GB and 120GB) at my workplace -- and have, on average, one of them go bad every week. Most of them suffer from two problems: 1) sectors going bad (confirmed using the SCSI card's BIOS), or 2) the drive literally falling off the SCSI bus (no indication of termination problems, controller issues, or otherwise), requiring a complete power-cycle of the drive before it will reappear (a soft reset won't fix it) on the bus. The latter indicates either crummy PCB design, shoddy components, or a major firmware bug.

And remember, people like to state that "SCSI drives are more robust/higher quality than ATA/SATA drives" -- which isn't necessarily true these days, but still: I wouldn't recommend Fujitsu even if they were the last hard drive manufacturer on the planet. That's just my opinion as someone who works with these drives in an enterprise environment 40 hours a week. :-)

Thanks for the in-depth reply, koitsu. It has really given me a lot of insight. I will buzz Bruce Allen with an email about this, and provide whatever information he needs. Not sure if it will help much, but it is worth a try. I suppose I was looking too deep into this SMART reading, that I overlooked some basic hints about my drive's health. I may, in fact, just replace this drive with an SSD in the future, once the prices drop some more. It seems that in theory, an SSD drive gives you less headaches, and aside from the maximum times a memory cell can be rewritten, there are very few things that can cause an SSD to go bad. Plus, the additional battery life is a welcoming perk.

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Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 13:44:05 EDT

koitsu posted : There are 3 issues here:

1) Your drive isn't in the internal smartctl database (used for handling SMART attribute tweaks):

Device Model:     FUJITSU MHZ2160BHSerial Number:    K665T8C2CE7NFirmware Version: 00000009User Capacity:    160,041,885,696 bytesDevice is:        Not in smartctl database [for details use: -P showall]

Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 13:22:09 EDT

OutOfMem posted :

said by koitsu:

Can you please provide full output from "smartctl -a {drive}"? Please don't use a front-end for this request -- I'd like to see the full, verbose output. I can help from that point going forward. (Wow, I sound like a CSR or something...)

And no, you cannot reset data stored in SMART. The only data that's possible to reset -- and only on very specific models of specific vendor drives -- is the SMART error log.

Upon a second look, it appears that the number of sectors that have been reallocated would make up a 4 PB (4,000 TB) hard drive, when my drive is only 160 GB! I just assumed the number would match the sector count of the entire drive, since it was so large, and should technically be at 0.

Here is the entire output of smartclt -a /dev/sda:

smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce AllenHome page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION ===Device Model:     FUJITSU MHZ2160BHSerial Number:    K665T8C2CE7NFirmware Version: 00000009User Capacity:    160,041,885,696 bytesDevice is:        Not in smartctl database [for details use: -P showall]ATA Version is:   8ATA Standard is:  ATA-8-ACS revision 3fLocal Time is:    Thu Jul  2 13:06:41 2009 EDTSMART 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:  (0x80)Offline data collection activitywas never started.Auto Offline Data Collection: Enabled.Self-test execution status:      (   0)The previous self-test routine completedwithout error or no self-test has ever been run.Total time to complete Offline data collection:  ( 649) seconds.Offline data collectioncapabilities:  (0x7b) SMART execute Offline immediate.Auto Offline data collection on/off support.Suspend Offline collection upon newcommand.Offline surface scan supported.Self-test supported.Conveyance Self-test supported.Selective Self-test supported.SMART capabilities:            (0x0003)Saves SMART data before enteringpower-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 routinerecommended polling time:  (  92) minutes.Conveyance self-test routinerecommended polling time:  (   2) minutes.SCT capabilities:        (0x003d)SCT Status supported.SCT Feature Control supported.SCT Data Table supported. SMART Attributes Data Structure revision number: 16Vendor Specific SMART Attributes with Thresholds:ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE  1 Raw_Read_Error_Rate     0x000f   100   100   046    Pre-fail  Always       -       209315  2 Throughput_Performance  0x0005   100   100   030    Pre-fail  Offline      -       28573696  3 Spin_Up_Time            0x0003   100   100   025    Pre-fail  Always       -       1  4 Start_Stop_Count        0x0032   099   099   000    Old_age   Always       -       544  5 Reallocated_Sector_Ct   0x0033   100   100   024    Pre-fail  Always       -       8589934592000  7 Seek_Error_Rate         0x000f   100   100   047    Pre-fail  Always       -       227  8 Seek_Time_Performance   0x0005   100   100   019    Pre-fail  Offline      -       0  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       29 10 Spin_Retry_Count        0x0013   100   100   020    Pre-fail  Always       -       0 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       45192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       9193 Load_Cycle_Count        0x0032   100   100   000    Old_age   Always       -       810194 Temperature_Celsius     0x0022   100   100   000    Old_age   Always       -       30 (Lifetime Min/Max 18/53)195 Hardware_ECC_Recovered  0x001a   100   100   000    Old_age   Always       -       516196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       452853760197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       0198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       0199 UDMA_CRC_Error_Count    0x003e   200   253   000    Old_age   Always       -       0200 Multi_Zone_Error_Rate   0x000f   100   100   060    Pre-fail  Always       -       24812203 Run_Out_Cancel          0x0002   100   100   000    Old_age   Always       -       1529021398973240 Head_Flying_Hours       0x003e   200   200   000    Old_age   Always       -       0 SMART Error Log Version: 1No Errors Logged SMART Self-test log structure revision number 1Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error# 1  Extended offline    Completed without error       00%        28         -# 2  Conveyance offline  Completed without error       00%        27         -# 3  Short offline       Completed without error       00%        27         - 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_testingSelective 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 ran all 3 tests, and they all passed. Even the "Reallocated Sector Count" claims to have no issues, which contradicts the raw value of 8589934592000.

GSmartControl says "NOTICE: This drive has a non-zero raw value, but there is no SMART warning yet. This could be an indication of future failures and/or potential data loss in bad sectors."

Here is where another problem lies. If I am to accept that this is just a glitch in the calculation, and that I do not have any bad/reallocated sectors, then what about in the future? How would I ever be able to use smartctl to know when my drive has reallocated some bad sectors? (A sign that the drive is failing.)

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Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 12:23:40 EDT

koitsu posted : Can you please provide full output from "smartctl -a {drive}"? Please don't use a front-end for this request -- I'd like to see the full, verbose output. I can help from that point going forward. (Wow, I sound like a CSR or something...)

And no, you cannot reset data stored in SMART. The only data that's possible to reset -- and only on very specific models of specific vendor drives -- is the SMART error log.
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Re: S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 10:36:10 EDT

PetePuma posted : What is the exact number? It could be a case where it's incorrectly treating a -1 or something as an unsigned number.
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S.M.A.R.T. shows obviously wrong attribute!

Thu, 02 Jul 2009 10:32:13 EDT

OutOfMem posted : When using GSmartControl (which is a frontend for smartctl), it reads my netbook hard drive of having a "Reallocated Sector Count" of the number of sectors that make up my hard drive. In other words, even though this is a brand new drive, it is saying that every single sector was reallocated, which is obviously impossible. It should be at 0, but for some reason smartctl is reading it at a ridiculously huge number. Is there a tool I can download to reset this attribute? Is smartctl not the most reliable way to get an accurate reading from your hard drive's S.M.A.R.T. attributes?
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