tjain90
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unable to mount root fs on unknown-block(179,2)

Sat Jan 11, 2014 12:41 pm

Hi Guys,

Yesterday i bought my Respberry Pi Model B and tried to install Respbian OS on Kingston MicroSD 8 GB .
I am using windows 7 and copied NOOBS files after formatting from SDFormatter. My Respberry Pi boots easily to NOOBS and i installed Respbian OS (even i tried to install others.) and after completion i received this error message : "PANIC: VFS Unable to mount root fs on unknown-block (179,2)
Entering kdb (current=0xcb846c80, pid 1) due to Keyboard Entry
". Please suggest how to solve this issue . I tried over more on internet but cant solve. can i solve this issue using my window 7 ?

Please help i m too much helpless i need to start my college project but i cant find way to get out from this issue!

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DougieLawson
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Re: unable to mount root fs on unknown-block(179,2)

Sat Jan 11, 2014 11:25 pm

Which version of NOOBS are you working with? If it's not 1.3.4 the download a new copy.
When you copied NOOBS how did you do that?

It's much easier to unzip the *.ZIP file directly on to the card.

When you've done that there should be 86 files in 16 directories on the card.

dev 179, subdev 2 is /dev/mmcblk0p2 so there's something fundamentally wrong because NOOBS puts the Raspbian filesystem on /dev/mmcblk0p6.

Get a new copy, try again.
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tjain90
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 10:05 am

Yes i have used the latest version of NOOBS 1.3.4 but still the error is same.
I am new to linux environment can you tell me something to solve this issue using windows 7 ?
Sorry to say but i cant understand this "ev 179, subdev 2 is /dev/mmcblk0p2 so there's something fundamentally wrong because NOOBS puts the Raspbian filesystem on /dev/mmcblk0p6.".
Please suggest me what to do next ?

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DougieLawson
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 2:21 pm

Boot NOOBS while holding the shift key on your keyboard.

That brings up the rescue system. You should be able to fix Raspbian from there.
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AndrewS
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 2:29 pm

@Dougie I'm also trying to get to the bottom of the problem here https://github.com/raspberrypi/noobs/issues/167 ;)

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DougieLawson
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 3:37 pm

Is the /boot/cmdline.txt correct? Does it point to the right partition for the rootfs?
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tjain90
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 5:36 pm

Hi Dougie,

I am using respbian OS:
My respbian cmdline.txt show:
"dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console =tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elavator=deadline rootwait" and i cannot login to recovery mode after entering root as my username i m unable to enter password (It behaves like my keyboard becomes disable and i can only press) and it shows invalid user !

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AndrewS
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Re: unable to mount root fs on unknown-block(179,2)

Sun Jan 12, 2014 5:48 pm

Your keyboard isn't disabled http://raspi.tv/2012/cant-type-password ... spberry-pi ;)
Please try logging in again...

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DougieLawson
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Re: unable to mount root fs on unknown-block(179,2)

Mon Jan 13, 2014 12:27 am

tjain90 wrote: and i cannot login to recovery mode after entering root as my username i m unable to enter password (It behaves like my keyboard becomes disable and i can only press) and it shows invalid user !
Linux doesn't echo any password when you enter it. It doesn't even echo asterisk characters.

What country are you in?
Does your keyboard have a normal QWERTYUIOP / ASDFGHJKL / ZXCVBNM layout?
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tjain90
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Re: unable to mount root fs on unknown-block(179,2)

Mon Jan 13, 2014 8:13 am

Hi Dougie,

I am from India and i m using normal USB keyboard. After login into root i have received the below error messsage :
http://www.elegantspares.com/Tarun/Error.jpg Please suggest me what to do next?

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AndrewS
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Re: unable to mount root fs on unknown-block(179,2)

Mon Jan 13, 2014 12:19 pm

tjain90 wrote:After login into root i have received the below error messsage :
http://www.elegantspares.com/Tarun/Error.jpg Please suggest me what to do next?
Your 'fdisk -l /dev/mmcblk0' output looks totally correct, so I've no idea how you ended up with /dev/mmcblk0p2 in your cmdline.txt :? :(

If you use NOOBS's built-in editor to edit the cmdline.txt to change the root=/dev/mmcblk0p2 part to root=/dev/mmcblk0p6 instead, you should find that your Pi boots okay :?:

tjain90
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Joined: Sat Jan 11, 2014 12:27 pm

Re: unable to mount root fs on unknown-block(179,2)

Tue Jan 14, 2014 3:39 am

Hi Andrew ,

If I change the cmdline text and press ok and after that I press esc key it does not save my setting . Because when I again boot up its shows the previous mmcblk0p2 only instead mmcblk0p6 .Can you tell me how to save the cmdline.text using noobs ?

tjain90
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Joined: Sat Jan 11, 2014 12:27 pm

Re: unable to mount root fs on unknown-block(179,2)

Mon Jan 20, 2014 4:53 pm

Thanks a lot Andrew and Dougie ! You guys are great.

I am able to solve this issue just by changing the mmcblk0p2 to mmcblk0p6 by putting SD card in Linux OS and saving the command line text.

Octopus3535
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Re: unable to mount root fs on unknown-block(179,2)

Tue May 06, 2014 4:26 am

nvm all working now
Last edited by Octopus3535 on Mon Jan 09, 2017 2:39 am, edited 1 time in total.

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DougieLawson
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Re: unable to mount root fs on unknown-block(179,2)

Tue May 06, 2014 8:52 am

If it has NOOBS on it already, hold the [SHIFT] key while booting, that should bring up the NOOBS recovery system.

If that doesn't work reformat your SDCard and put a fresh copy of NOOBS on it.
Note: Having anything humorous in your signature is completely banned on this forum. Wear a tin-foil hat and you'll get a ban.

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AndrewS
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Re: unable to mount root fs on unknown-block(179,2)

Tue May 06, 2014 8:59 pm

Sometimes a USB keyboard won't get recognised until after the firmware / linux has booted i.e. if you hold down SHIFT and then power on, some keyboards will send the keypress to NOOBS, and some won't.

So the most reliable way to do it is to "keep tapping" SHIFT until the NOOBS recovery GUI pops up :D

tktbjp
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Joined: Mon Nov 03, 2014 2:58 am

Re: unable to mount root fs on unknown-block(179,2)

Mon Nov 03, 2014 3:04 am

Hi,

I have started using pi B+ board with the NOBOS version 1.3.10.
I still face above error when kernel starts booting.

My command line (according to previous posts) is same and points to mmcblk0p2 for rootfs. Does it need to change to mmcblk0p6 as per some comments?
I also do not know which cmdline.txt file to change? Where this file is present? There is no /boot folder present when searches from recovery option. How should I create this file using linux pc? What is to be mounted in linux PC?

Please help..I am stuck with B+.

Thanks,
Tkt

tktbjp
Posts: 7
Joined: Mon Nov 03, 2014 2:58 am

Re: unable to mount root fs on unknown-block(179,2)

Mon Nov 03, 2014 6:24 am

Actually it is simple to use the recovery mode.
I entered recovery mode and pressed alt-F2 to loging as root. Changing cmdline.txt from the GUI does not work.

After logging in as root with password raspberry, check if there is any /boot directory. Most probably it will not be present.
If not then create it using mkdir /boot
Then use vi editor to create cmdline.txt.
#cd /boot
#vi cmdline.txt

in vi editor change the root to mmcblk0p6.
My cmdline.txt contents looks like
dwc_otg.lpm_enable=0 console=ttyAM0,115200 console=tty1 root=/dev/mmcblk0p6 rootfstype=ext4 elevator=deadline rootwait

save the file.
then it is important to do sync.
#sync

Then boot the board. Cross check using GUI if cmdline is really changed.
My PI B+ is working now :geek:

Barney_Bear2002
Posts: 16
Joined: Fri Apr 10, 2015 4:33 pm

Re: unable to mount root fs on unknown-block(179,2)

Tue Jul 07, 2015 3:22 pm

tktbjp wrote:Actually it is simple to use the recovery mode.
I entered recovery mode and pressed alt-F2 to loging as root. Changing cmdline.txt from the GUI does not work.

After logging in as root with password raspberry, check if there is any /boot directory. Most probably it will not be present.
If not then create it using mkdir /boot
Then use vi editor to create cmdline.txt.
#cd /boot
#vi cmdline.txt

in vi editor change the root to mmcblk0p6.
My cmdline.txt contents looks like
dwc_otg.lpm_enable=0 console=ttyAM0,115200 console=tty1 root=/dev/mmcblk0p6 rootfstype=ext4 elevator=deadline rootwait

save the file.
then it is important to do sync.
#sync

Then boot the board. Cross check using GUI if cmdline is really changed.
My PI B+ is working now :geek:
I've got the save problem with my raspberry pi b but as well my keyboard which normally works doesn't seem to be found
Thanks to everyone that helps

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