From: Matthew B. <lib...@su...> - 2008-02-27 01:02:12
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Just a note that my users have reported that smartctl works on the Solid State Drive in the new MacBook Air. I was wondering if they would use it or not. Any idea what the unknown attributes are? Here's the log: smartctl version 5.38 [i386-apple-darwin9.0.0] Copyright (C) 2002-7 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Device Model: MCCOE64GEMPP Serial Number: SE805C0159 Firmware Version: 2.9.09 User Capacity: 60,022,480,896 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 7 ATA Standard is: ATA/ATAPI-7 T13 1532D revision 4a Local Time is: Tue Feb 26 19:06:03 2008 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" "=== START OF READ SMART DATA SECTION === 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: ( 120) seconds. Offline data collection capabilities: (0x5b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. 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: ( 15) minutes." "=== START OF READ SMART DATA SECTION === 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 0x000f 099 099 051 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0007 084 084 001 Pre-fail Always - 2617344 9 Power_On_Hours 0x0033 099 099 000 Pre-fail Always - 8 12 Power_Cycle_Count 0x0033 099 099 000 Pre-fail Always - 111 184 Unknown_Attribute 0x0033 099 099 000 Pre-fail Always - 0 187 Reported_Uncorrect 0x0033 100 100 000 Pre-fail Always - 0 188 Unknown_Attribute 0x0033 099 099 000 Pre-fail Always - 0 190 Airflow_Temperature_Cel 0x0023 045 045 000 Pre-fail Always - 0 195 Hardware_ECC_Recovered 0x001a 200 200 000 Old_age Always - 0 196 Reallocated_Event_Count 0x0033 099 099 000 Pre-fail Always - 0 197 Current_Pending_Sector 0x0012 099 099 000 Old_age Always - 0 198 Offline_Uncorrectable 0x003e 100 100 000 Old_age Always - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 201 Soft_Read_Error_Rate 0x0032 100 100 002 Old_age Always - 0 202 TA_Increase_Count 0x0032 100 100 002 Old_age Always - 0 232 Unknown_Attribute 0x0013 084 084 002 Pre-fail Always - 3393" "=== START OF READ SMART DATA SECTION === SMART Error Log Version: 1 No Errors Logged" -- Matthew Butch "fiat justicia ruat colelum" (let justice be done though the heavens may fall) Sent with Mac OS X Leopard Mail 3.1 (914/915) |
From: Bruce A. <ba...@gr...> - 2008-02-27 12:39:21
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Hi Matt, That's very interesting to know. For fun I googled and found the datasheet (Samsung) for the SSD: http://www.datasheetpro.com/233348_download_MCCOE64GEMPP-01A_datasheet.html This confirms that SMART is supported but does not give any significant details. According to the docs, self-tests are supported. So you should try running a short and/or long self-test (-t short / -t long). Only other comment is that the reallocated sector count raw values are very high. I don't know what that means. Perhaps there are many non-functional storage cells that are reallocated. Cheers, Bruce On Tue, 26 Feb 2008, Matthew Butch wrote: > Just a note that my users have reported that smartctl works on the > Solid State Drive in the new MacBook Air. I was wondering if they > would use it or not. Any idea what the unknown attributes are? Here's > the log: > > smartctl version 5.38 [i386-apple-darwin9.0.0] Copyright (C) 2002-7 > Bruce Allen > Home page is http://smartmontools.sourceforge.net/ > === START OF INFORMATION SECTION === > Device Model: MCCOE64GEMPP > Serial Number: SE805C0159 > Firmware Version: 2.9.09 > User Capacity: 60,022,480,896 bytes > Device is: Not in smartctl database [for details use: -P showall] > ATA Version is: 7 > ATA Standard is: ATA/ATAPI-7 T13 1532D revision 4a > Local Time is: Tue Feb 26 19:06:03 2008 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" > > "=== START OF READ SMART DATA SECTION === > 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: ( 120) seconds. > Offline data collection > capabilities: (0x5b) SMART execute Offline immediate. > Auto Offline data collection on/off support. > Suspend Offline collection upon new > command. > 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: ( 15) minutes." > > "=== START OF READ SMART DATA SECTION === > 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 0x000f 099 099 051 Pre-fail > Always - 0 > 5 Reallocated_Sector_Ct 0x0007 084 084 001 Pre-fail > Always - 2617344 > 9 Power_On_Hours 0x0033 099 099 000 Pre-fail > Always - 8 > 12 Power_Cycle_Count 0x0033 099 099 000 Pre-fail > Always - 111 > 184 Unknown_Attribute 0x0033 099 099 000 Pre-fail > Always - 0 > 187 Reported_Uncorrect 0x0033 100 100 000 Pre-fail > Always - 0 > 188 Unknown_Attribute 0x0033 099 099 000 Pre-fail > Always - 0 > 190 Airflow_Temperature_Cel 0x0023 045 045 000 Pre-fail > Always - 0 > 195 Hardware_ECC_Recovered 0x001a 200 200 000 Old_age > Always - 0 > 196 Reallocated_Event_Count 0x0033 099 099 000 Pre-fail > Always - 0 > 197 Current_Pending_Sector 0x0012 099 099 000 Old_age > Always - 0 > 198 Offline_Uncorrectable 0x003e 100 100 000 Old_age > Always - 0 > 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age > Always - 0 > 201 Soft_Read_Error_Rate 0x0032 100 100 002 Old_age > Always - 0 > 202 TA_Increase_Count 0x0032 100 100 002 Old_age > Always - 0 > 232 Unknown_Attribute 0x0013 084 084 002 Pre-fail > Always - 3393" > > "=== START OF READ SMART DATA SECTION === > SMART Error Log Version: 1 > No Errors Logged" > > > > -- > > Matthew Butch > > "fiat justicia ruat colelum" > (let justice be done though the heavens may fall) > > Sent with Mac OS X Leopard Mail 3.1 (914/915) > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Smartmontools-support mailing list > Sma...@li... > https://lists.sourceforge.net/lists/listinfo/smartmontools-support > |
From: Roy B. <roy...@gl...> - 2008-02-27 16:38:39
|
Bruce> Only other comment is that the reallocated sector count raw Bruce> values are very high. I don't know what that Bruce> means. Perhaps there are many non-functional storage cells Bruce> that are reallocated. Could this be a result of wear levelling, perhaps? -roy |
From: Bruce A. <ba...@gr...> - 2008-02-27 19:42:46
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> Bruce> Only other comment is that the reallocated sector count raw > Bruce> values are very high. I don't know what that > Bruce> means. Perhaps there are many non-functional storage cells > Bruce> that are reallocated. > > Could this be a result of wear levelling, perhaps? Hi Roy, That's a good explanation. If I understand it right, the device firmware forces reallocation of blocks that have been through too many read/write cycles and hence are no longer reliable. Is that what you are suggesting? Cheers, Bruce |
From: Roy B. <roy...@gl...> - 2008-02-28 09:37:48
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Bruce> That's a good explanation. If I understand it right, the Bruce> device firmware forces reallocation of blocks that have Bruce> been through too many read/write cycles and hence are no Bruce> longer reliable. Is that what you are suggesting? Not quite was I was suggesting. Wear levelling in SSDs causes the mapping between logical and physical blocks to be frequently remapped on write - possibly as frequently as every write. The idea is to ensure that 'popular' blocks in the filesystem move about the physical device, so that all physical blocks get written to roughly equally, to try to avoid any one physical block going through too many write cycles. I was speculating that maybe the author of the SMART code in this disk was (ab)using this attribute to track the number of times that blocks have been moved about by the wear levelling algorithm. On the face of it this would seem a somewhat bizarre choice, but I can quite imagine that the bad block management is quite tightly integrated with the wear levelling algorithm, so it's not completely implausible. -roy |
From: Bruce A. <ba...@gr...> - 2008-02-28 10:51:48
|
OK, I get it. Thanks for the details! This seems like a reasonable explanation of what might be happening. Bruce On Thu, 28 Feb 2008, Roy Badami wrote: > Bruce> That's a good explanation. If I understand it right, the > Bruce> device firmware forces reallocation of blocks that have > Bruce> been through too many read/write cycles and hence are no > Bruce> longer reliable. Is that what you are suggesting? > > > Not quite was I was suggesting. > > Wear levelling in SSDs causes the mapping between logical and physical > blocks to be frequently remapped on write - possibly as frequently as > every write. The idea is to ensure that 'popular' blocks in the > filesystem move about the physical device, so that all physical blocks > get written to roughly equally, to try to avoid any one physical block > going through too many write cycles. > > I was speculating that maybe the author of the SMART code in this disk > was (ab)using this attribute to track the number of times that blocks > have been moved about by the wear levelling algorithm. On the face of > it this would seem a somewhat bizarre choice, but I can quite imagine > that the bad block management is quite tightly integrated with the > wear levelling algorithm, so it's not completely implausible. > > -roy > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Smartmontools-support mailing list > Sma...@li... > https://lists.sourceforge.net/lists/listinfo/smartmontools-support > |