Unable to mount root fs or unknown block
 

I am having problems booting up.

I am getting "Unable to mount root fs or unknown block."

I have tried dpkg and fsck, but the problem persists.

So are we back to having to guess the details again????

AGAIN:

• WHAT have you tried EXACTLY? What commands did you type in where, and what were the results?
• What kind of hardware (disks/controllers/RAID level if any, etc.)?
• Version/distro of Linux?? Or do we again have to guess that it's the same machine you've talked about before?
• Anything changed/updated/patched lately?
• Based on errors, that is not the entire error message...what's the rest?

Again, you've been here for years...read the "Question Guidelines".

Short answer: your system is damaged. Longer answer: Google has many suggested solutions for the part of the error you posted; if you're not going to provide details, try looking there first:
https://ubuntuforums.org/showthread.php?t=1751574

I provided details, but you have trouble reading.

When you can respond positively, I will answer you.

I am not letting you mess up my day when there are others who CHEERFULLY help.

Grow up. You omitted ANY details past part of an error message, despite being asked. If you have trouble understanding this, after repeatedly being told to provide such things, there's little anyone can do for you. If being asked to provide details by someone WHO IS TRYING TO HELP YOU SOLVE YOUR PROBLEM is 'messing up your day', then seek help.

Answer the questions asked of you. Apparently, you being nice to others isn't something you have to do, is it?

Let's run this down...you say you 'provided details', which consisted of:

• Saying you can't boot
• Part of an error message
• Saying you "tried dkpg and fsck"

Mind explaining exactly how those 'details' can help anyone to help you??? Then you display such a great attitude by saying "you have trouble reading", to someone trying to help you? Pat yourself on the back for that.

This is not being nice.

<So are we back to having to guess the details again???? >

When you leave crap like this out of your messages, I will gladly answer your questions.

And what is so difficult in understanding this ?

Ubuntu-mate-16.04-desktop-amd64

Others have no problem. :-)

I don't care if you answer them or not...my system(s) aren't having problems. Don't answer them, and NO ONE will be able to help you. Don't like it? Then don't keep doing it. Third thread you've started where you have trouble with basic comprehension of "give us details". Every time you're asked, you whine and moan.
And what is the problem with YOU understanding "People have MANY THINGS LISTED on profiles/signatures, and they MAY NOT BE TALKING ABOUT THAT SAME MACHINE WHEN THEY POST" Can you not comprehend THAT either???? Or saying "This is about the 16.04 system in my signature", to let folks know what you're talking about?

Even saying "Ubuntu 16.04" STILL gives no details. AGAIN, since you're not understanding this:

• You posted PART of an error message
• Say you "tried dpkg and fsck"..don't actually bother saying WHERE you typed that in, why, with what options, etc.
• Tell us ZERO about your system
• Tell us anything that may have changed

...as you were asked before. Do you not understand these things????

Would it be feasible to download this BootRepair .iso ?
(and boot=run it, *like*: just looking at a 'live distro')
It gives you the option to post a paste.ubuntu.com where others can see diag info,
or to [try to] automagically 'repair' what is wrong (99%safe I believe, but you can wait for others to look at the 'paste', to be 100% safe)

It may work just fine, but since the OP doesn't give ANY details about the system, how it got to this state (indications of running 'dpkg'???), etc, who knows what the result will be.

And apparently, I got placed on his ignore list, according to another nasty PM (which makes 2 from this 'good person'), for trying to help him.

Thanks a lot, I will try it and post my results.

Attached is my screenshot of 'same'/similar error.
I used grub 'e', to change "root=sda1" to just sda, to cause it.
The theory behind it (I love digging to lowest details, opposite of typical computer user;) ) is: like `ls badnam` returns "no such.../not found",
the kernel begins to access the / fs by mount'ing it. IF it can't (for whatever reason), this is its "error msg". Dead end.
Or I could have written garbage onto /dev/sda1. Or loaded a 'bad' kernel (no sd/ext4fs driver; 2nd attachment is yesterday's attempt at 'tinyconfig+' kernel, missing lvm&SATA!). Or ...
That's why ANY [frustrated?] 'repairPerson' asks: "what did you do?" ("more info needed")

I do not understand what you are saying ?

Did you find a fix for the error message ?

I ran a disk check and fix.

If it does not help, I will restore a previous image using redo backup.

Oh, sorry, NOone understands what I write, so you're not alone! :cry:

No, I'm showing -sample- 'causes'; the 'fix' would be: don't 'cause' it!

You'd need to -not- do (what you did, *before* the panic!)...
(the error msg is very-NOT-sufficient to isolate one of MANY possible causes)

It's not a fsck issue. (issue: the kernel you loaded can't find a 'good' / )

Will you be able to run that BootRepair .iso?

p.s. "restore a previous image using redo backup."
scares me, because I have no idea/concept of what that is
(not your 'fault'; I simply don't know that concept!)
So, "be careful" ... don't want things to get worse!

I'm lost on the basic situation here:
IF the system is 'dead' (won't boot),
how can it 'run' any 'restore'?

Is there another computer? Is this a new install/computer? [re]Moveable disk?
Or is that 'redo [pgm?]', something you boot, like the .iso I recommended?

Sorry, I can't 'picture' what's going on...

Another attempt to explain what I'm thinking: (pic here)

Can you 'catch' grub, hit 'e', scroll [way]down to the line that says [LIKE]:
linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1

You need to 'confirm' the /boot/<kernel> is 'proper', and also the 'root='
(did either this line change, or the kernel-file, or *esp* something 'happen' to the root fs?)

One of those 2 pieces got 'broken'. It 'dead-ends' there.

So, 1) that kernel loads and starts to run (BUT maybe bad/wrong kernel file! img2)
2) it can't 'mount' *that* root. TheEnd. [WHY can't it mount it??? my attached img1]

The BoorRepair .iso will deeply-investigate ALL this, and post it to a webpage, for any&all to see/help! Like: http://paste.ubuntu.com/23851335, with 1click (of its 'post' button); it won't change anything (unless you click its 'repair' button)

Redo backup did not restore an image correctly. Guess it occasionally does not work.

So I went to Plan B and re-installed Ubuntu-Mate.
I did nothing that I am aware of to cause the panic.

One day, it just happened when I booted up the computer.