I've seen similar cases where a USB drive appears to fail but the SMART reports success. The most recent was a 500 GB disk which had internally a Seagate Barracuda SATA drive. It appeared to work well until I sent it a largish (7GB) tarball. As well as SMART I ran a surface check and exercise, all passed. The tar kept failing. I can't test further, the disk has been broken up for destruction, but I wonder if the problem is the disk or the USB/SATA conversion board? If there is some sort of buffer in the interface that is filling, then the behaviour you describe makes sense. I have no proof or details, it's just a thought that occurred to me as I was breaking it up. >-----Original Message----- >From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On >Behalf Of Bob Hepple >Sent: 27 January 2014 08:11 >To: centos at centos.org >Subject: [CentOS] smartctl: is my disc dying? > >I've got a 1Tb USB disc that appears to be dying - eg it took about 10 days >(!) to run 'badblocks -nsv /dev/sdc' and it only did less than 2% in that time. >Read access became _really_ slow. > >So there's definitely something amiss and I've got it offline. > >There's no drama about the content as I have other backups and I'm resigned >to junking the thing, but I'm curious about the fact that smartctl doesn't seem >to report any errors. I tried a short and a long test but nothing in there seems >to be alarming - in fact it says PASSED!! - but the output is pretty opaque and >maybe I've been foxed by ambiguity. Anyone care to comment on it? > >Here it is: > >[root at nina bhepple]# smartctl /dev/sdc -a smartctl 5.43 2012-06-30 r3573 >[i686-linux-2.6.32-358.23.2.el6.i686] (local >build) >Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net > >=== START OF INFORMATION SECTION === >Model Family: Western Digital Caviar Green >Device Model: WDC WD10EAVS-00M4B0 >Serial Number: WD-WCAV5A574187 >LU WWN Device Id: 5 0014ee 2aef3c352 >Firmware Version: 01.00A01 >User Capacity: 1,000,204,886,016 bytes [1.00 TB] >Sector Size: 512 bytes logical/physical >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: Mon Jan 27 17:43:33 2014 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: (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. >Total time to complete Offline >data collection: (18780) seconds. >Offline data collection >capabilities: (0x7b) SMART execute Offline immediate. > Auto Offline data collection on/off support. > Suspend Offline collection upon new > command. > Offline surface scan supported. > Self-test supported. > 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: ( 217) minutes. >Conveyance self-test routine >recommended polling time: ( 5) minutes. >SCT capabilities: (0x3037) SCT Status supported. > SCT Feature Control supported. > SCT Data Table supported. > >SMART Attributes Data Structure revision number: 16 Vendor Specific SMART >Attributes with Thresholds: >ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED >WHEN_FAILED RAW_VALUE > 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always > - 0 > 3 Spin_Up_Time 0x0027 114 107 021 Pre-fail Always > - 7283 > 4 Start_Stop_Count 0x0032 091 091 000 Old_age Always > - 9764 > 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always > - 0 > 7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always > - 0 > 9 Power_On_Hours 0x0032 080 080 000 Old_age Always > - 14907 > 10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always > - 0 > 11 Calibration_Retry_Count 0x0032 100 100 000 Old_age Always > - 0 > 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always > - 181 >192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always > - 82 >193 Load_Cycle_Count 0x0032 186 186 000 Old_age Always > - 44531 >194 Temperature_Celsius 0x0022 098 083 000 Old_age Always > - 49 >196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always > - 0 >197 Current_Pending_Sector 0x0032 192 192 000 Old_age Always > - 1423 >198 Offline_Uncorrectable 0x0030 196 196 000 Old_age Offline > - 700 >199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always > - 0 >200 Multi_Zone_Error_Rate 0x0008 001 001 000 Old_age Offline > - 793265 > >SMART Error Log Version: 1 >No Errors Logged > >SMART Self-test log structure revision number 1 >Num Test_Description Status Remaining LifeTime(hours) > LBA_of_first_error ># 1 Extended offline Completed: read failure 90% 14545 > 1141581559 ># 2 Short offline Completed: read failure 90% 14545 > 1141577005 > >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 >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. > > > >_______________________________________________ >CentOS mailing list >CentOS at centos.org >http://lists.centos.org/mailman/listinfo/centos This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. 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