I am trying to recover whatever data I can from a bad partition on a hard drive. Unfortunately fsck failed to resolve the issue. The output from mount is as follows:
$ sudo mount /dev/sda3 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/sda3,
dmesg output is as follows:
[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 output is as follows:
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
.. removed some excessive output...
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
The sector affected is the first sector of the partition.
dumpe2fs, tune2fs, and debugfs all fail to read the drive, even if I use alternative superblocks (found using mke2fs -n /dev/sda2). Curiously if I do a dd on the affected sector I get no errors.
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
I'm not too hopeful about recovering my data, but interested in the process that would be required to attempt this. Should i write zeros over the affected sectors or is there a better approach?
Thanks
