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我正在尝试从硬盘驱动器上的损坏分区中恢复尽可能多的数据。不幸的是 fsck 未能解决该问题。 mount的输出如下：
$ sudo mount /dev/sda3 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/sda3,
dmesg 输出如下：
[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 complete
Smartctl输出如下：
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
..删除了一些过多的输出...
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
受影响的扇区是分区的第一个扇区。
即使我使用替代超级块（使用 mke2fs -n /dev/sda2 找到），dumpe2fs、tune2fs 和 debugfs 都无法读取驱动器。奇怪的是，如果我对受影响的扇区进行 dd 操作，我不会收到任何错误。
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
我对恢复数据不太抱有希望，但对尝试此操作所需的过程感兴趣。我应该在受影响的扇区上写零还是有更好的方法？
谢谢
答案1
使用解救安装了 dd （它将忽略读取错误），然后您可以fsck使用各种参数在转储的映像上运行-b。
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.