[SOLVED] ext4 partition just went missing; dd if=the_partition writes 0 bytes.
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Well done!
I would just loop mount the partition and see if you can read it:
Code:
# Just to be safe:
chmod 0440 /path/to/p1
# Link the rescued partition to a loop device:
losetup /dev/loop3 /path/to/p1
# Create a temporary mount point:
mkdir /mnt/temp
# See if the mount works (probably not):
mount /dev/loop3 0t ext4 /mnt/temp -o ro,norecovery,noload
if that doesn't work (and not due to not recognizing "norecovery,noload") see if you can get the location of an alternative superblock (man 'fsck' wrt mke2fs; 'man mke2fs') and run fsck.ext4 on it with "-f -v -n" (but never with "-a" or "-p"!). If you have testdisk you could try
Code:
testdisk /debug /log /dev/loop3
and see if you can "browse" the file system: ( Proceed > Choose partition table type ("none" because its a partition) > Advanced > Undelete). If that doesn't work look at "testdisk.log" for clues.
mount /dev/loop3 0t ext4 /mnt/temp -o ro,norecovery,noload
fails with usual bad superblock | wrong fs type .
Quote:
If you have testdisk you could try
Code:
testdisk /debug /log /dev/loop3
and see if you can "browse" the file system: ( Proceed > Choose partition table type ("none" because its a partition) > Advanced > Undelete). If that doesn't work look at "testdisk.log" for clues.
after Advanced i dont get Undelete option but it does give my partition.it does gives alternate locations of the superblock.
there also a list option. and it works.
testdisk.log
Code:
Using locale 'C'.
Tue Nov 13 09:32:09 2012
Command line: TestDisk /debug /log p1
TestDisk 6.13, Data Recovery Utility, November 2011
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org
OS: Linux, kernel 3.4.5-1-ARCH (#1 SMP PREEMPT Mon Jul 16 21:35:54 CEST 2012) x86_64
Compiler: GCC 4.7
Compilation date: 2012-11-05T15:00:38
ext2fs lib: 1.42.4, ntfs lib: libntfs-3g, reiserfs lib: 0.3.0.5, ewf lib: none
Hard disk list
Disk p1 - 943 GB / 878 GiB - CHS 114734 255 63, sector size=512
Partition table type (auto): None
Disk p1 - 943 GB / 878 GiB
Partition table type: None
Interface Advanced
recover_EXT2: "e2fsck -b 98304 -B 4096 device" may be needed
P ext4 0 0 1 114733 227 54 1843200000 [wd]
EXT4 Large file Sparse superblock Backup superblock, 943 GB / 878 GiB
Interface Advanced
recover_EXT2: "e2fsck -b 98304 -B 4096 device" may be needed
P ext4 0 0 1 114733 227 54 1843200000 [wd]
EXT4 Large file Sparse superblock Backup superblock, 943 GB / 878 GiB
search_superblock
block_group_nr 1
recover_EXT2: "e2fsck -b 32768 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=1/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 262144 (block=32768, blocksize=4096)
block_group_nr 3
recover_EXT2: "e2fsck -b 98304 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=3/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 262144 (block=32768, blocksize=4096)
block_group_nr 3
recover_EXT2: "e2fsck -b 98304 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=3/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 786432 (block=98304, blocksize=4096)
block_group_nr 5
recover_EXT2: "e2fsck -b 163840 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=5/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 1310720 (block=163840, blocksize=4096)
block_group_nr 7
recover_EXT2: "e2fsck -b 229376 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=7/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 1835008 (block=229376, blocksize=4096)
block_group_nr 9
recover_EXT2: "e2fsck -b 294912 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=9/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 2359296 (block=294912, blocksize=4096)
block_group_nr 25
recover_EXT2: "e2fsck -b 819200 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=25/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 6553600 (block=819200, blocksize=4096)
block_group_nr 27
recover_EXT2: "e2fsck -b 884736 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=27/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 7077888 (block=884736, blocksize=4096)
block_group_nr 49
recover_EXT2: "e2fsck -b 1605632 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=49/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 12845056 (block=1605632, blocksize=4096)
block_group_nr 81
recover_EXT2: "e2fsck -b 2654208 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=81/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 21233664 (block=2654208, blocksize=4096)
block_group_nr 125
recover_EXT2: "e2fsck -b 4096000 -B 4096 device" may be needed
recover_EXT2: s_block_group_nr=125/7031, s_mnt_count=0/4294967295, s_blocks_per_group=32768, s_inodes_per_group=8192
recover_EXT2: s_blocksize=4096
recover_EXT2: s_blocks_count 230399999
recover_EXT2: part_size 1843199992
Ext2 superblock found at sector 32768000 (block=4096000, blocksize=4096)
ext4 0 0 1 114733 227 46 1843199992 [wd]
superblock 32768, blocksize=4096 [wd]
superblock 98304, blocksize=4096 [wd]
superblock 163840, blocksize=4096 [wd]
superblock 229376, blocksize=4096 [wd]
superblock 294912, blocksize=4096 [wd]
superblock 819200, blocksize=4096 [wd]
superblock 884736, blocksize=4096 [wd]
superblock 1605632, blocksize=4096 [wd]
superblock 2654208, blocksize=4096 [wd]
superblock 4096000, blocksize=4096 [wd]
To repair the filesystem using alternate superblock, run
fsck.ext4 -p -b superblock -B blocksize device
SIGINT detected! TestDisk has been killed.
Quote:
if that doesn't work (and not due to not recognizing "norecovery,noload") see if you can get the location of an alternative superblock (man 'fsck' wrt mke2fs; 'man mke2fs') and run fsck.ext4 on it with "-f -v -n" (but never with "-a" or "-p"!).
i am bit confused here.
should i run mke2fs or e2fsck (fsck.ext4 does not have all these options) ? or both if yes in what order ?
anyway i did run e2fsk. it just keep outputing lots of dash seprated numbers .
i am bit confused here.
should i run mke2fs or e2fsck (fsck.ext4 does not have all these options) ? or both if yes in what order ?
My reply was in this order:
- try loop mounting, or else
- find an alternative superblock (using 'mke2fs -n') and
- run fsck "-v -t -n", or else
- run testdisk.
Quote:
Originally Posted by ununun
anyway i did run e2fsk. it just keep outputing lots of dash seprated numbers .
Did you mount the partiton read-only? What was the fsck command line you used? Did you run fsck with the arguments that testdisk.log suggested?
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