From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Goryachev Subject: Uneven wear on raid1 devices Date: Mon, 25 Jan 2016 16:29:02 +1100 Message-ID: <56A5B29E.3020708@websitemanagers.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid List-Id: linux-raid.ids Hi all, I was hoping to get some advice on why my two SSD's seem to be wearing unevenly, when they are both in the same raid1 array. First, the array information: # mdadm --misc --detail /dev/md0 /dev/md0: Version : 1.2 Creation Time : Fri Jun 14 00:42:04 2013 Raid Level : raid1 Array Size : 499975360 (476.81 GiB 511.97 GB) Used Dev Size : 499975360 (476.81 GiB 511.97 GB) Raid Devices : 2 Total Devices : 2 Persistence : Superblock is persistent Intent Bitmap : Internal Update Time : Mon Jan 25 16:20:11 2016 State : active Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Name : flail:0 (local to host flail) UUID : 81b25e43:787b0bc4:f934d006:a726aa89 Events : 1240606 Number Major Minor RaidDevice State 2 8 17 0 active sync /dev/sdb1 1 8 49 1 active sync /dev/sdd1 # smartctl -A /dev/sdb|grep Wear 177 Wear_Leveling_Count 0x0013 093 093 000 Pre-fail Always - 248 # smartctl -A /dev/sdd|grep Wear 177 Wear_Leveling_Count 0x0013 074 074 000 Pre-fail Always - 915 Equally, we can see a different amount of data written to each drive: # smartctl -A /dev/sdb|grep Written 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 7169916114 # smartctl -A /dev/sdd|grep Written 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 24013780683 I'm stuck wondering why one drive is getting so many more writes than the other, and is there some way to "swap" this so that the other drive will get the heavier load over the next 12 months? In theory, this suggests that one drive has 74% life remaining, and the other has 93% (unless I'm reading that incorrectly...), while 74% is still a lot, I guess I would prefer to prevent it getting too much lower and needing replacement.... Any suggestions or advice greatly appreciated. Full output of smartctl -x below for each drive: # smartctl -x /dev/sdb smartctl 5.41 2011-06-09 r3365 [i686-linux-3.2.0-4-686-pae] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: Samsung SSD 840 PRO Series Serial Number: S1AXNSAF702689E LU WWN Device Id: 5 002538 5a02701b8 Firmware Version: DXM06B0Q User Capacity: 512,110,190,592 bytes [512 GB] Sector Size: 512 bytes logical/physical Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 4c Local Time is: Mon Jan 25 16:28:01 2016 AEDT 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: (53956) 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: ( 35) minutes. SCT capabilities: (0x003d) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 1 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE 5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0 9 Power_On_Hours -O--CK 098 098 000 - 6435 12 Power_Cycle_Count -O--CK 099 099 000 - 1 177 Wear_Leveling_Count PO--C- 093 093 000 - 248 179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0 181 Program_Fail_Cnt_Total -O--CK 100 100 010 - 0 182 Erase_Fail_Count_Total -O--CK 100 100 010 - 0 183 Runtime_Bad_Block PO--C- 100 100 010 - 0 187 Reported_Uncorrect -O--CK 100 100 000 - 0 190 Airflow_Temperature_Cel -O--CK 072 060 000 - 28 195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0 199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0 235 Unknown_Attribute -O--C- 100 100 000 - 0 241 Total_LBAs_Written -O--CK 099 099 000 - 7169972542 ||||||_ K auto-keep |||||__ C event count ||||___ R error rate |||____ S speed/performance ||_____ O updated online |______ P prefailure warning General Purpose Log Directory Version 1 SMART Log Directory Version 1 [multi-sector log support] GP/S Log at address 0x00 has 1 sectors [Log Directory] GP/S Log at address 0x01 has 1 sectors [Summary SMART error log] GP/S Log at address 0x02 has 1 sectors [Comprehensive SMART error log] GP/S Log at address 0x03 has 1 sectors [Ext. Comprehensive SMART error log] GP/S Log at address 0x06 has 1 sectors [SMART self-test log] GP/S Log at address 0x07 has 1 sectors [Extended self-test log] GP/S Log at address 0x09 has 1 sectors [Selective self-test log] GP/S Log at address 0x10 has 1 sectors [NCQ Command Error] GP/S Log at address 0x11 has 1 sectors [SATA Phy Event Counters] GP/S Log at address 0x30 has 1 sectors [Reserved] GP/S Log at address 0x80 has 16 sectors [Host vendor specific log] GP/S Log at address 0x81 has 16 sectors [Host vendor specific log] GP/S Log at address 0x82 has 16 sectors [Host vendor specific log] GP/S Log at address 0x83 has 16 sectors [Host vendor specific log] GP/S Log at address 0x84 has 16 sectors [Host vendor specific log] GP/S Log at address 0x85 has 16 sectors [Host vendor specific log] GP/S Log at address 0x86 has 16 sectors [Host vendor specific log] GP/S Log at address 0x87 has 16 sectors [Host vendor specific log] GP/S Log at address 0x88 has 16 sectors [Host vendor specific log] GP/S Log at address 0x89 has 16 sectors [Host vendor specific log] GP/S Log at address 0x8a has 16 sectors [Host vendor specific log] GP/S Log at address 0x8b has 16 sectors [Host vendor specific log] GP/S Log at address 0x8c has 16 sectors [Host vendor specific log] GP/S Log at address 0x8d has 16 sectors [Host vendor specific log] GP/S Log at address 0x8e has 16 sectors [Host vendor specific log] GP/S Log at address 0x8f has 16 sectors [Host vendor specific log] GP/S Log at address 0x90 has 16 sectors [Host vendor specific log] GP/S Log at address 0x91 has 16 sectors [Host vendor specific log] GP/S Log at address 0x92 has 16 sectors [Host vendor specific log] GP/S Log at address 0x93 has 16 sectors [Host vendor specific log] GP/S Log at address 0x94 has 16 sectors [Host vendor specific log] GP/S Log at address 0x95 has 16 sectors [Host vendor specific log] GP/S Log at address 0x96 has 16 sectors [Host vendor specific log] GP/S Log at address 0x97 has 16 sectors [Host vendor specific log] GP/S Log at address 0x98 has 16 sectors [Host vendor specific log] GP/S Log at address 0x99 has 16 sectors [Host vendor specific log] GP/S Log at address 0x9a has 16 sectors [Host vendor specific log] GP/S Log at address 0x9b has 16 sectors [Host vendor specific log] GP/S Log at address 0x9c has 16 sectors [Host vendor specific log] GP/S Log at address 0x9d has 16 sectors [Host vendor specific log] GP/S Log at address 0x9e has 16 sectors [Host vendor specific log] GP/S Log at address 0x9f has 16 sectors [Host vendor specific log] GP/S Log at address 0xa0 has 16 sectors [Device vendor specific log] SMART Extended Comprehensive Error Log Version: 1 (1 sectors) No Errors Logged SMART Extended Self-test Log Version: 1 (1 sectors) No self-tests have been logged. [To run self-tests, use: smartctl -t] 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. Error unknown SCT Temperature History Format Version (3), should be 2. SCT Error Recovery Control: Read: Disabled Write: Disabled SATA Phy Event Counters (GP Log 0x11) ID Size Value Description 0x0001 2 0 Command failed due to ICRC error 0x0002 2 0 R_ERR response for data FIS 0x0003 2 0 R_ERR response for device-to-host data FIS 0x0004 2 0 R_ERR response for host-to-device data FIS 0x0005 2 0 R_ERR response for non-data FIS 0x0006 2 0 R_ERR response for device-to-host non-data FIS 0x0007 2 0 R_ERR response for host-to-device non-data FIS 0x0008 2 0 Device-to-host non-data FIS retries 0x0009 2 11 Transition from drive PhyRdy to drive PhyNRdy 0x000a 2 11 Device-to-host register FISes sent due to a COMRESET 0x000b 2 0 CRC errors within host-to-device FIS 0x000d 2 0 Non-CRC errors within host-to-device FIS 0x000f 2 0 R_ERR response for host-to-device data FIS, CRC 0x0010 2 0 R_ERR response for host-to-device data FIS, non-CRC 0x0012 2 0 R_ERR response for host-to-device non-data FIS, CRC 0x0013 2 0 R_ERR response for host-to-device non-data FIS, non-CRC # smartctl -x /dev/sdd smartctl 5.41 2011-06-09 r3365 [i686-linux-3.2.0-4-686-pae] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: Samsung SSD 840 PRO Series Serial Number: S12SNEAD204208R LU WWN Device Id: 5 002538 5501d20d0 Firmware Version: DXM04B0Q User Capacity: 512,110,190,592 bytes [512 GB] Sector Size: 512 bytes logical/physical Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 4c Local Time is: Mon Jan 25 16:26:24 2016 AEDT 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: (53956) 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: ( 35) minutes. SCT capabilities: (0x003d) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 1 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE 5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0 9 Power_On_Hours -O--CK 095 095 000 - 23178 12 Power_Cycle_Count -O--CK 099 099 000 - 8 177 Wear_Leveling_Count PO--C- 074 074 000 - 915 179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0 181 Program_Fail_Cnt_Total -O--CK 100 100 010 - 0 182 Erase_Fail_Count_Total -O--CK 100 100 010 - 0 183 Runtime_Bad_Block PO--C- 100 100 010 - 0 187 Reported_Uncorrect -O--CK 100 100 000 - 0 190 Airflow_Temperature_Cel -O--CK 073 058 000 - 27 195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0 199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0 235 Unknown_Attribute -O--C- 099 099 000 - 6 241 Total_LBAs_Written -O--CK 099 099 000 - 24013821507 ||||||_ K auto-keep |||||__ C event count ||||___ R error rate |||____ S speed/performance ||_____ O updated online |______ P prefailure warning General Purpose Log Directory Version 1 SMART Log Directory Version 1 [multi-sector log support] GP/S Log at address 0x00 has 1 sectors [Log Directory] GP/S Log at address 0x01 has 1 sectors [Summary SMART error log] GP/S Log at address 0x02 has 1 sectors [Comprehensive SMART error log] GP/S Log at address 0x03 has 1 sectors [Ext. Comprehensive SMART error log] GP/S Log at address 0x06 has 1 sectors [SMART self-test log] GP/S Log at address 0x07 has 1 sectors [Extended self-test log] GP/S Log at address 0x09 has 1 sectors [Selective self-test log] GP/S Log at address 0x10 has 1 sectors [NCQ Command Error] GP/S Log at address 0x11 has 1 sectors [SATA Phy Event Counters] GP/S Log at address 0x30 has 1 sectors [Reserved] GP/S Log at address 0x80 has 16 sectors [Host vendor specific log] GP/S Log at address 0x81 has 16 sectors [Host vendor specific log] GP/S Log at address 0x82 has 16 sectors [Host vendor specific log] GP/S Log at address 0x83 has 16 sectors [Host vendor specific log] GP/S Log at address 0x84 has 16 sectors [Host vendor specific log] GP/S Log at address 0x85 has 16 sectors [Host vendor specific log] GP/S Log at address 0x86 has 16 sectors [Host vendor specific log] GP/S Log at address 0x87 has 16 sectors [Host vendor specific log] GP/S Log at address 0x88 has 16 sectors [Host vendor specific log] GP/S Log at address 0x89 has 16 sectors [Host vendor specific log] GP/S Log at address 0x8a has 16 sectors [Host vendor specific log] GP/S Log at address 0x8b has 16 sectors [Host vendor specific log] GP/S Log at address 0x8c has 16 sectors [Host vendor specific log] GP/S Log at address 0x8d has 16 sectors [Host vendor specific log] GP/S Log at address 0x8e has 16 sectors [Host vendor specific log] GP/S Log at address 0x8f has 16 sectors [Host vendor specific log] GP/S Log at address 0x90 has 16 sectors [Host vendor specific log] GP/S Log at address 0x91 has 16 sectors [Host vendor specific log] GP/S Log at address 0x92 has 16 sectors [Host vendor specific log] GP/S Log at address 0x93 has 16 sectors [Host vendor specific log] GP/S Log at address 0x94 has 16 sectors [Host vendor specific log] GP/S Log at address 0x95 has 16 sectors [Host vendor specific log] GP/S Log at address 0x96 has 16 sectors [Host vendor specific log] GP/S Log at address 0x97 has 16 sectors [Host vendor specific log] GP/S Log at address 0x98 has 16 sectors [Host vendor specific log] GP/S Log at address 0x99 has 16 sectors [Host vendor specific log] GP/S Log at address 0x9a has 16 sectors [Host vendor specific log] GP/S Log at address 0x9b has 16 sectors [Host vendor specific log] GP/S Log at address 0x9c has 16 sectors [Host vendor specific log] GP/S Log at address 0x9d has 16 sectors [Host vendor specific log] GP/S Log at address 0x9e has 16 sectors [Host vendor specific log] GP/S Log at address 0x9f has 16 sectors [Host vendor specific log] GP/S Log at address 0xa0 has 16 sectors [Device vendor specific log] SMART Extended Comprehensive Error Log Version: 1 (1 sectors) No Errors Logged SMART Extended Self-test Log Version: 1 (1 sectors) No self-tests have been logged. [To run self-tests, use: smartctl -t] 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. Error unknown SCT Temperature History Format Version (3), should be 2. SCT Error Recovery Control: Read: Disabled Write: Disabled SATA Phy Event Counters (GP Log 0x11) ID Size Value Description 0x0001 2 0 Command failed due to ICRC error 0x0002 2 0 R_ERR response for data FIS 0x0003 2 0 R_ERR response for device-to-host data FIS 0x0004 2 0 R_ERR response for host-to-device data FIS 0x0005 2 0 R_ERR response for non-data FIS 0x0006 2 0 R_ERR response for device-to-host non-data FIS 0x0007 2 0 R_ERR response for host-to-device non-data FIS 0x0008 2 0 Device-to-host non-data FIS retries 0x0009 2 11 Transition from drive PhyRdy to drive PhyNRdy 0x000a 2 11 Device-to-host register FISes sent due to a COMRESET 0x000b 2 0 CRC errors within host-to-device FIS 0x000d 2 0 Non-CRC errors within host-to-device FIS 0x000f 2 0 R_ERR response for host-to-device data FIS, CRC 0x0010 2 0 R_ERR response for host-to-device data FIS, non-CRC 0x0012 2 0 R_ERR response for host-to-device non-data FIS, CRC 0x0013 2 0 R_ERR response for host-to-device non-data FIS, non-CRC