Howto: rescue corrupt data partition?


8 posts
by peepo » Wed Jul 10, 2013 3:02 pm
cannot find howto,

using wheezy, was working, believe loose connection may have resulted in corrupted partition.
had been using at time...

troubleshooting wiki: only red light is on and steady
other cards boot fine.

boot partition /dev/sdb1 mounts fine in other linux or osx system and appears to be fine

parted and fdisk info appended

any advice or suggestions appreciated!

Jonathan

$ sudo parted /dev/sdb2
GNU Parted 2.3
Using /dev/sdb2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print

Error: /dev/sdb2: unrecognised disk label

$ sudo fdisk /dev/sdb2

Command (m for help): p

Disk /dev/sdb2: 7759 MB, 7759462400 bytes
241 heads, 62 sectors/track, 1014 cylinders, total 15155200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x3dd6cacc

Device Boot Start End Blocks Id System

but where are the numerals?
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by joan » Wed Jul 10, 2013 3:15 pm
fdisk is used to partition disks. /dev/sdb1 is a partition on disk /dev/sdb.
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by rpdom » Wed Jul 10, 2013 3:56 pm
Try sudo fdisk -l /dev/sdb

To check the filesystem, use sudo fsck /dev/sdb2 . This may repair any corruption if it is not too bad.
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by DrMag » Wed Jul 10, 2013 4:06 pm
I just yesterday ran into a similar problem; using a SanDisk 16 GB class 10 card. The Pi running on it has been running fine for months, then on a reboot (after updating some software) it has the same error: PWR light on steady, nothing else happens. The partitions all mount just fine on my desktop. My other Pi's card (same type) boots it up just fine. Power supply is just fine; it really seems to be an issue with the specific card.

I actually tried to reflash the card with a fresh installation, and it still won't boot up.

Is there something I need to do to the card to get it to work again, or is there something else going on that's causing the problem?
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by joan » Wed Jul 10, 2013 4:09 pm
Given that you have already reflashed the card then https://www.sdcard.org/downloads/formatter_4/ can't do any harm.
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by duberry » Wed Jul 10, 2013 4:43 pm
joan wrote:Given that you have already reflashed the card then https://www.sdcard.org/downloads/formatter_4/ can't do any harm.

they say
"Using generic formatting utilities may result in less than optimal performance for your memory cards."
but Require runing windows and mac osx only :?
:lol:
lend me your arms, fast as thunderbolts, for a pillow on my journey.
If the environment was a bank, would it be too big to fail
so long; and thanks for all the pi
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by peepo » Wed Jul 10, 2013 9:17 pm
rpdom easy when you know how.... wfm! tx again
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by peepo » Thu Oct 31, 2013 6:17 pm
Unable to mount 16GB File system
Error mounting: mount: wrong fs type, bad option, bad superblock on /dev/sdb2,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

--
[611277.583249] Buffer I/O error on device sdb2, logical block 158
[611277.583252] lost page write due to I/O error on sdb2
[611277.583258] Buffer I/O error on device sdb2, logical block 159
[611277.583261] lost page write due to I/O error on sdb2
[611277.583265] Buffer I/O error on device sdb2, logical block 160
[611277.583268] lost page write due to I/O error on sdb2
[611277.583762] JBD2: recovery failed
[611277.583766] EXT4-fs (sdb2): error loading journal
[611278.219809] sd 11:0:0:0: [sdb] No Caching mode page present
[611278.219814] sd 11:0:0:0: [sdb] Assuming drive cache: write through

--

sudo fsck /dev/sdb2
fsck from util-linux 2.20.1
e2fsck 1.42.5 (29-Jul-2012)
/dev/sdb2: recovering journal
Superblock needs_recovery flag is clear, but journal has data.
Run journal anyway<y>? yes
fsck.ext4: unable to set superblock flags on /dev/sdb2


/dev/sdb2: ********** WARNING: Filesystem still has errors **********
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