Data-Recovery
從 AMNR 硬碟錯誤中恢復 (ext4)
我正在嘗試從硬碟驅動器上的錯誤分區中恢復任何數據。不幸的是 fsck 未能解決問題。mount 的輸出如下：
$ sudo mount /dev/sda3 /mnt/ mount: wrong fs type, bad option, bad superblock on /dev/sda3,dmesg 輸出如下：
[77027.447708] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 [77027.447714] ata1.00: irq_stat 0x40000001 [77027.447719] ata1.00: failed command: READ DMA [77027.447726] ata1.00: cmd c8/00:08:00:28:c3/00:00:00:00:00/e8 tag 25 dma 4096 in res 51/01:00:00:28:c3/00:00:08:00:00/e8 Emask 0x9 (media error) [77027.447730] ata1.00: status: { DRDY ERR } [77027.447733] ata1.00: error: { AMNF } [77027.448901] ata1.00: configured for UDMA/100 [77027.448915] sd 0:0:0:0: [sda] tag#25 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08 [77027.448919] sd 0:0:0:0: [sda] tag#25 Sense Key : 0x3 [current] [77027.448922] sd 0:0:0:0: [sda] tag#25 ASC=0x13 ASCQ=0x0 [77027.448926] sd 0:0:0:0: [sda] tag#25 CDB: opcode=0x28 28 00 08 c3 28 00 00 00 08 00 [77027.448929] blk_update_request: I/O error, dev sda, sector 147007488 [77027.448934] Buffer I/O error on dev sda3, logical block 0, async page read [77027.448967] ata1: EH completeSmartctl 輸出如下：
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 0x000f 200 200 051 Pre-fail Always - 108 3 Spin_Up_Time 0x0003 242 185 021 Pre-fail Always - 2891 4 Start_Stop_Count 0x0032 081 081 000 Old_age Always - 19060 5 Reallocated_Sector_Ct 0x0033 199 199 140 Pre-fail Always - 1 7 Seek_Error_Rate 0x000f 200 200 051 Pre-fail Always - 0 9 Power_On_Hours 0x0032 076 076 000 Old_age Always - 17595 10 Spin_Retry_Count 0x0013 100 100 051 Pre-fail Always - 0 11 Calibration_Retry_Count 0x0012 100 100 051 Old_age Always - 0 12 Power_Cycle_Count 0x0032 084 084 000 Old_age Always - 16934 190 Airflow_Temperature_Cel 0x0022 056 028 045 Old_age Always In_the_past 44 194 Temperature_Celsius 0x0022 106 078 000 Old_age Always - 44 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0012 182 182 000 Old_age Always - 761 198 Offline_Uncorrectable 0x0010 182 182 000 Old_age Offline - 763 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 1 200 Multi_Zone_Error_Rate 0x0009 161 127 051 Pre-fail Offline - 1311..刪除了一些過多的輸出…
After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 01 51 00 00 28 c3 e8 Error: AMNF at LBA = 0x08c32800 = 147007488 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 08 00 28 c3 08 00 21:23:05.524 READ DMA ca 00 08 20 31 bf 02 00 21:23:05.524 WRITE DMA ca 00 08 20 30 bf 02 00 21:23:05.523 WRITE DMA ca 00 08 60 2f bf 02 00 21:23:05.523 WRITE DMA ca 00 08 08 2f bf 02 00 21:23:05.523 WRITE DMA受影響的扇區是分區的第一個扇區。
dumpe2fs、tune2fs 和 debugfs 都無法讀取驅動器，即使我使用替代超級塊（使用 mke2fs -n /dev/sda2 找到）。奇怪的是，如果我對受影響的扇區進行 dd 操作，我不會出錯。
sudo dd if=/dev/sda of=/dev/null bs=512 skip=147007488 count=1 1+0 records in 1+0 records out 512 bytes copied, 0.000177462 s, 2.9 MB/s我不太希望恢復我的數據，但對嘗試此操作所需的過程很感興趣。我應該在受影響的扇區上寫零還是有更好的方法？
謝謝
使用ddrescue insted of dd （它將忽略讀取錯誤），然後您可以
fsck使用各種-b參數在轉儲的圖像上執行。男人fsck：
-b superblock Instead of using the normal superblock, use an alternative superblock specified by superblock. This option is normally used when the primary superblock has been corrupted. The loca‐ tion of the backup superblock is dependent on the filesystem's blocksize. For filesystems with 1k blocksizes, a backup superblock can be found at block 8193; for filesystems with 2k blocksizes, at block 16384; and for 4k blocksizes, at block 32768.