I had my RPi2 (used as a local web-dev server) crashed after making an update using SSH from a distant computer. During the upgrade, the console started to display there was a bus problem, and after having waited for quite a while I hard-rebooted the Pi, and used a screen to see what happensed Well, I'm stuck with the kernel-panic message mentionned in the title. The Pi is running Raspbian (no NOOBS !).
I found here a post with almost the same issue : Kernel panic-not syncing: VFS: unable to mount root fs on unknown- block(179,6) running Raspbian on top of NOOBS. Unfortunately, the solutions proposed don't work for me.
- I can't enter recovery mode using SHIFT
- I can edit the cmdline.txt file (either on Windows or Ubuntu), I can replace
root=/dev/mmcblk0p2byroot=/dev/mmcblk0p6. However, those changes are not taken into account, and I still have the same message when rebooting.
Just in case, I've testes several power supplies, without success.
How can I force cmdline.txt changes to be taken into account ? Is there another way to proceed in order to get my system back ?
EDIT #1 :
I've been using an Ubuntu live USB version. The USB device has a capacity of 16 Gb, so has the micro SD used with the Raspi. I used fdisk to differentiate both. Here are the results for the Pi micro SD :
Disque /dev/sdc : 14,7 GiB, 15811477504 octets, 30881792 secteurs
Unités : sectors of 1 * 512 = 512 octets
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0cf63fa8
Périphérique Amorçage Start Fin Secteurs Size Id Type
/dev/sdc1 8192 131071 122880 60M c W95 FAT32 (LBA)
/dev/sdc2 131072 30881791 30750720 14,7G 83 Linux
Then, I created a directory sudo mkdir /media/sdcard/ and mounted the first one : sudo mount /dev/sdc1 /media/sdcard/. No surprise here, I get that I already had when inserting the device (automatically mounted by Ubuntu) : the boot part, with cmdline.txt, config.txt, and the overlay directory.
I am interested as you may have guessed by the files contained by sdc2. Hence, I repeated the operation for this volume and I got this :
sudo mount /dev/sdc2 /media/sdcard/
mount: wrong fs type, bad option, bad superblock on /dev/sdc2,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
Here is what I got after running dmesg | tail as suggested :
[ 3242.691618] blk_update_request: I/O error, dev sdc, sector 3538944
[ 3242.691633] JBD2: IO error reading journal superblock
[ 3242.691639] EXT4-fs (sdc2): error loading journal
[ 3518.191904] sd 9:0:0:0: [sdc] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_SENSE
[ 3518.191910] sd 9:0:0:0: [sdc] tag#0 Sense Key : Hardware Error [current]
[ 3518.191913] sd 9:0:0:0: [sdc] tag#0 Add. Sense: No additional sense information
[ 3518.191918] sd 9:0:0:0: [sdc] tag#0 CDB: Read(10) 28 00 00 36 00 00 00 00 08 00
[ 3518.191921] blk_update_request: I/O error, dev sdc, sector 3538944
[ 3518.191936] JBD2: IO error reading journal superblock
[ 3518.191941] EXT4-fs (sdc2): error loading journal
I've already tried to "repair" the faulty block yesterday, but my skills are limited. It obviously didn't work.
EDIT #2 :
Ran fsck as suggested. "Reading attempt of a block from the filesystem produced a truncated reading. Execute fsck manually"
ubuntu@ubuntu:~/wpscan$ sudo fsck -a /dev/sdc2
fsck de util-linux 2.27.1
Erreur de lecture du bloc 425984 (La tentative de lecture d'un bloc depuis le système de fichiers a produit une lecture tronquée).
/dev/sdc2: INCONSISTENCE INATTENDUE ; EXÉCUTEZ fsck MANUELLEMENT.
(i.e., sans options -a ou -p)
Tried to do it manually, but don't know what the best choices are in my case : shall I ignore the error ? shall I force re-writing ? in case of an invalid log for the superblock, shall I erase it ?
