ISO boot check disk found error

Asked by Johnny

When I create my iso on a usb key and install it on a specific laptop the iso disk check informs me of an error on one or two files. The installation with preseed fails.

If I test my usb key on another model of laptop or on a vm virtualbox the disk check of my image shows no error and the automatic installation goes on without problem.

I don't understand why this disk check has errors, when it's the same usb key with the same iso that works on the other models or on virtualbox.

How can we see these files in errors? Do you have any idea?
thank you

Question information

Language:
English Edit question
Status:
Solved
For:
Cubic Edit question
Assignee:
No assignee Edit question
Solved by:
Johnny
Solved:
Last query:
Last reply:
Revision history for this message
Johnny (johnnybee) said :
#1

If i'm using usb key with official Ubuntu ISO desktop 20.04.2.0 version, i don't have errors on iso boot check disk step

Revision history for this message
Johnny (johnnybee) said :
#2

Same errors with flash bios update

Revision history for this message
Johnny (johnnybee) said :
#3

If i rebuild an iso with ubuntu 20.04.2.0 and not 20.04.1, i don't have errors on check disk boot.

Revision history for this message
Cubic PPA (cubic-wizard) said :
#4

(1)
To confirm, you see an error on the boot screen, after it shows the following message?
   "Press Ctrl+C to cancel filesystem checks in progress"?

(2)
Are you talking about the disk check when you are booting the generated ISO?

(3)
Or, are you talking about the disk check when you are booting OS *AFTER* installing from the generated ISO?

(4)
When you say, "Same errors with flash bios update", you mean that you updated your system BIOS thinking it would resolve the problem, but afterwards, you had the same errors?

(5)
Please confirm which version of Cubic you are using?
Which OS and version did you run Cubic in?
Which OS and version did you customize?

Revision history for this message
Johnny (johnnybee) said :
#5

Hi Cubic PPA !

(1)
Yes, that's exactly it, I'm also trying to understand how this phase takes place.
The live is mounted in memory and the check disk verifies the integrity of the files? How can we know which files are in error?

(2)
Yes, that's exactly

(3)
The error appends when i'm booting the generated ISO

(4)
Yes, that's exactly it, I updated the bios, and I got the same error

(5)
I'm using Cubic version 2021.03.45
I'm customizing Ubuntu 20.04

Do you think my chroot filesystem was corrupted ? But i don't understand why it works fine with virtualbox or another laptop model.
Or some firmeware included in 20.04.2.0 ?

Now i'm using 20.04.2.0 for build my custom ISO

regards

Revision history for this message
Johnny (johnnybee) said :
#6

Hi,

With the F1 key we can see the verbose check a startup boot iso check disk

Revision history for this message
Cubic PPA (cubic-wizard) said :
#7

OK, thanks for the answers.

One more question, which tool did you use to create the USB key?

(Also, one trick I have used in the past is to record a video of certain portions of the boot process on my mobile phone. Then play it back, and pause it to see error messages that you would otherwise miss).

Revision history for this message
Johnny (johnnybee) said :
#8

Hello,

I'm using ubuntu usb-creator in virtualbox (maybe it is not a good idea) or Balena Etcher on Debian or dd low level tool.

Thank you for the tricks.

Sometimes the custom version fail to boot and the official version is booting well. I don't know why.

Actually my custom iso 20.04.2.0 working well on old and new laptop models

Regards

Revision history for this message
Cubic PPA (cubic-wizard) said :
#9

usb-creator and Virtualbox should be fine.
Be sure to allocate enough memory and disk space to the virtual machine.
I recommend at least 4GB memory and at least 25~30GB disk space.

I'm surprised your ISOs do not boot sometimes.
It could be a write issue, when the USB key is created.

Try manually validating the files (this is the same check that is performed when the ISO is booted and displays the message "Press Ctrl+C to cancel filesystem checks in progress").

(1)
Mount your custom ISO USB key.

(2)
Open a terminal to the location of the ISO.
You will see the following list of files:
        boot
        casper
        dists
        EFI
        install
        isolinux
        md5sum.txt
        pool
        preseed
        README.diskdefines
        ubuntu

(3)
Execute the following command:

        $ md5sum --check md5sum.txt | grep FAILED

If there are any files on the ISO that do not have the correct checksum, they will be listed.

Revision history for this message
Johnny (johnnybee) said :
#10

Hello CubicPPA,

Thank you for your return and these informations