RAID5 schlägt während der Wiederherstellung (mdadm) fehl: Gibt es eine Chance zur erneuten Synchronisierung?

Mein RAID5 stirbt, weil beim Wiederherstellen einer ausgefallenen Festplatte auf einer anderen Festplatte Lesefehler aufgetreten sind und eine Wiederherstellung nicht möglich ist. Ich möchte nur wissen, ob es möglich ist, nur einen Teil der verbleibenden Daten wiederherzustellen - die meisten sollten sowieso vorhanden sein.

Ich habe keine vollständige Sicherung, da 25 TB Daten nicht einfach zu sichern sind. Ich weiß: Kein Backup - keine Gnade. Das ist okay. Aber ich möchte es versuchen. Ich kann mir nicht vorstellen, dass es nicht möglich ist, diesen Überfall wieder zum Leben zu erwecken.

Meine aktuelle Konfiguration:

• RAID5 mit 5 Festplatten (WD WD60EFRX Red SA3), 6 TB
• OS ist auf extra SSD
• Ubuntu 16.04 mit einem Mdadm-Software-Raid

Eines Tages /dev/sdaschlug folgende Nachricht fehl:

This is an automatically generated mail message from mdadm running on ***  A Fail event had been detected on md device /dev/md/0.  It could be related to component device /dev/sda1.  Faithfully yours, etc.  P.S. The /proc/mdstat file currently contains the following:  Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0 [raid1] [raid10]  md0 : active raid5 sde1[5] sdb1[1] sda1[0](F) sdc1[7] sdd1[6] 23441545216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [5/4] [_UUUU] bitmap: 4/44 pages [16KB], 65536KB chunk  unused devices: <none> 

Also habe ich folgendes gemacht:

Überprüfte die Festplatte:

$ sudo smartctl -a /dev/sda smartctl 6.5 2016-01-24 r4214 [x86_64-linux-4.4.0-93-generic] (local build) Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org  === START OF INFORMATION SECTION === Model Family: Western Digital Red Device Model: WDC WD60EFRX-68MYMN1 Serial Number: WD-WX41D75LN5CP LU WWN Device Id: 5 0014ee 2620bfa28 Firmware Version: 82.00A82 User Capacity: 6.001.175.126.016 bytes [6,00 TB] Sector Sizes: 512 bytes logical, 4096 bytes physical Rotation Rate: 5700 rpm Device is: In smartctl database [for details use: -P show] ATA Version is: ACS-2, ACS-3 T13/2161-D revision 3b SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s) Local Time is: Tue Jan 30 22:02:37 2018 CET 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: FAILED! Drive failure expected in less than 24 hours. SAVE ALL DATA. See vendor-specific Attribute list for failed Attributes.  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: ( 7004) 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: ( 723) minutes. Conveyance self-test routine recommended polling time: ( 5) minutes. SCT capabilities: (0x303d) SCT Status supported. SCT Error Recovery Control 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 001 001 051 Pre-fail Always FAILING_NOW 37802 3 Spin_Up_Time 0x0027 217 189 021 Pre-fail Always - 8141 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 26 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 077 077 000 Old_age Always - 17248 10 Spin_Retry_Count 0x0032 100 253 000 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 100 253 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 26 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 4 193 Load_Cycle_Count 0x0032 194 194 000 Old_age Always - 19683 194 Temperature_Celsius 0x0022 113 103 000 Old_age Always - 39 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 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]  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. 

Überprüfte den Überfall:

$ sudo mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Tue Dec 15 22:20:33 2015 Raid Level : raid5 Array Size : 23441545216 (22355.60 GiB 24004.14 GB) Used Dev Size : 5860386304 (5588.90 GiB 6001.04 GB) Raid Devices : 5 Total Devices : 5 Persistence : Superblock is persistent  Intent Bitmap : Internal  Update Time : Tue Jan 30 22:07:30 2018 State : clean Active Devices : 5 Working Devices : 5 Failed Devices : 0 Spare Devices : 0  Layout : left-symmetric Chunk Size : 512K  Name : fractal.hostname:0 (local to host fractal.hostname) UUID : e9bdcf76:c5e04a88:32d5dfa6:557bdeaf Events : 80222  Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/sda1 1 8 17 1 active sync /dev/sdb1 7 8 33 2 active sync /dev/sdc1 6 8 49 3 active sync /dev/sdd1 5 8 65 4 active sync /dev/sde1 # cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10] md0 : active raid5 sde1[5] sdb1[1] sda1[0] sdc1[7] sdd1[6] 23441545216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [5/5] [UUUUU] bitmap: 4/44 pages [16KB], 65536KB chunk  unused devices: <none> 

So war das Laufwerk jetzt nicht ausgefallen, sondern ging weiter. Also entfernte ich es aus dem Überfall,

# mdadm /dev/md0 --fail /dev/sda1 mdadm: set /dev/sda1 faulty in /dev/md0  # mdadm /dev/md0 --remove /dev/sda1 mdadm: hot removed /dev/sda1 from /dev/md0 

startete neu und fügte den neuen hinzu, nachdem er die Partitionstabellen kopiert hatte:

sgdisk --backup=gpt_backup /dev/sdb sgdisk --load-backup=gpt_backup /dev/sda sgdisk -G /dev/sda  mdadm --manage /dev/md0 -a /dev/sda1 

Während der Wiederherstellung schlug ein anderes Laufwerk ( /dev/sdb) wie folgt fehl:

This is an automatically generated mail message from mdadm running on fractal.hostname  A Fail event had been detected on md device /dev/md/0.  It could be related to component device /dev/sdb1.  Faithfully yours, etc.  P.S. The /proc/mdstat file currently contains the following:  Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10]  md0 : active raid5 sda1[8] sdb1[1](F) sde1[5] sdc1[7] sdd1[6]      23441545216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [5/3] [__UUU]      [===================>.]  recovery = 99.5% (5835184192/5860386304) finish=595.0min speed=703K/sec      bitmap: 0/44 pages [0KB], 65536KB chunk  unused devices: <none> 

Offensichtlich konnte er keinen Abschnitt zur Wiederherstellung lesen:

This message was generated by the smartd daemon running on:    host name:  fractal   DNS domain: hostname  The following warning/error was logged by the smartd daemon:  Device: /dev/sdb [SAT], 167 Currently unreadable (pending) sectors  Device info: WDC WD60EFRX-68MYMN1, S/N:WD-WX41D75LN3YP, WWN:5-0014ee-20cb6e76b, FW:82.00A82, 6.00 TB  For details see host's SYSLOG.  You can also use the smartctl utility for further investigation. The original message about this issue was sent at Wed Jan 31 14:15:20 2018 CET Another message will be sent in 24 hours if the problem persists. 

Ich habe das gleiche Verfahren dreimal ausprobiert und jedes Mal versagte es auf dieselbe Weise (nur wenn ein anderer Fortschritt erreicht wurde, manchmal 60%, manchmal 99,5%).

Nach mehreren Versuchen habe ich das Array neu zusammengestellt, aber es endete auf die gleiche Weise:

# cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : inactive sdb1[1](S) sde1[5](S) sdc1[7](S) sdd1[6](S) sda1[8](S) 29301944199 blocks super 1.2  unused devices: <none> # mdadm -D /dev/md0 /dev/md0: Version : 1.2 Raid Level : raid0 Total Devices : 5 Persistence : Superblock is persistent  State : inactive  Name : fractal.hostname:0 (local to host fractal.hostname) UUID : e9bdcf76:c5e04a88:32d5dfa6:557bdeaf Events : 133218  Number Major Minor RaidDevice  - 8 1 - /dev/sda1 - 8 17 - /dev/sdb1 - 8 33 - /dev/sdc1 - 8 49 - /dev/sdd1 - 8 65 - /dev/sde1 # mdadm --assemble --update=resync --force /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 mdadm: forcing event count in /dev/sdb1(1) from 132262 upto 133218 mdadm: clearing FAULTY flag for device 0 in /dev/md0 for /dev/sda1 mdadm: Marking array /dev/md0 as 'clean' mdadm: failed to RUN_ARRAY /dev/md0: Input/output error # mdadm -D /dev/md0 /dev/md0: Version : 1.2 Raid Level : raid0 Total Devices : 2 Persistence : Superblock is persistent  State : inactive  Name : fractal.hostname:0 (local to host fractal.hostname) UUID : e9bdcf76:c5e04a88:32d5dfa6:557bdeaf Events : 133218  Number Major Minor RaidDevice  - 8 49 - /dev/sdd1 - 8 65 - /dev/sde1 # cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : inactive sde1[5](S) sdd1[6](S) 11720776864 blocks super 1.2  unused devices: <none> # mdadm --assemble --update=resync --force /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 mdadm: /dev/sdd1 is busy - skipping mdadm: /dev/sde1 is busy - skipping mdadm: Merging with already-assembled /dev/md/0 mdadm: Marking array /dev/md/0 as 'clean' mdadm: /dev/md/0 has been started with 4 drives (out of 5) and 1 spare. # mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Tue Dec 15 22:20:33 2015 Raid Level : raid5 Array Size : 23441545216 (22355.60 GiB 24004.14 GB) Used Dev Size : 5860386304 (5588.90 GiB 6001.04 GB) Raid Devices : 5 Total Devices : 5 Persistence : Superblock is persistent  Intent Bitmap : Internal  Update Time : Sat Feb 10 09:42:03 2018 State : clean, degraded, recovering Active Devices : 4 Working Devices : 5 Failed Devices : 0 Spare Devices : 1  Layout : left-symmetric Chunk Size : 512K  Rebuild Status : 0% complete  Name : fractal.hostname:0 (local to host fractal.hostname) UUID : e9bdcf76:c5e04a88:32d5dfa6:557bdeaf Events : 133220  Number Major Minor RaidDevice State 8 8 1 0 spare rebuilding /dev/sda1 1 8 17 1 active sync /dev/sdb1 7 8 33 2 active sync /dev/sdc1 6 8 49 3 active sync /dev/sdd1 5 8 65 4 active sync /dev/sde1 

Sehen Sie eine Chance, meine Daten ohne Verlust wiederherzustellen? Gibt es eine Möglichkeit, einen Teil meiner Daten wiederherzustellen? Natürlich konnte er bis zu 99,5% synchronisieren, aber ich konnte es nicht verwenden.

Vielen Dank im Voraus.