Could not find the root block device in UUID=........

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Hello everybody, i'm a new gentoo user.It's a while that i tried to install this fabolous distro after i read a lot of posts.
It's a small Acer Laptot Aspire E11 con ssd (eMMC 32GB)
I used "genkernel --menuconfig all" for set vfat fs support, scsi support and all file system.

I don't have any errors during the installation, but when i reboot i get "Could not find the root block device in UUID=d5777................."
-Please specify another value or:
-press Enter for the same
type shell for a shell
type "q" to skip
I used system rescue cd for installation, grub for the bootloader.
the partition are:

mmcblk0p1 uefi 512M
mmcblk0p2 / 27.6G
mmcblk0p3 swap 1G

this is my fstab:

DONAHUE · Posted: Sat Jul 16, 2016 1:45 pm Post subject:

Boot the sysresccd, run parted -l | wgetpaste -t and blkid | wgetpaste -t and lspci -k | wgetpaste -t .
Mount the gentoo partitions and run wgetpaste -t /mnt/gentoo/boot/grub/grub.cfg and wgetpaste -t /mnt/gentoo/usr/src/linux/.config.
Post the url's returned by wgetpaste.
What was the exact command used to install grub?
If you retained windows and are planning to dual boot suggest a look at https://wiki.gentoo.org/wiki/UEFI_Dual_boot_with_Windows_7/8 (also works for win10) .
Recommend scrapping grub; using rEFInd with efi stub kernel for dual boot or efi stub kernel for single boot (with or without rEFInd).
_________________
Defund the FCC.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks for reply Donahue.

1)
-parted -l | wgetpaste - t https://bpaste.net/show/11230919a2e3
-blkid | wgetpaste -t https://bpaste.net/show/824ea469ad15
-lspci -k | wgetpaste -t https://bpaste.net/show/325653f74fd7

After Mount the gentoo partitions like so:

NeddySeagoon · Posted: Sat Jul 16, 2016 2:44 pm Post subject:

beetterfly,

Welcome to Gentoo.

I don't see any storage devices of any sorf attached via the PCI bus or its descendants.
This makes me suspect its on the USB subsystem. Please post the output of lsusb, so we can check that.
If that guess is correct, you need to add rootwait to the kernel command line in grub.cfg

What happens now is that the kernel will try to mount root before the usb subsystem is started, so it will fail.
Subsequent attempts should work though.

When you get to

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks for welcome NeddySeagoon.

1)
- lsusb

NeddySeagoon · Posted: Sat Jul 16, 2016 3:39 pm Post subject:

beetterfly,

Thats really useful information.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks a lot NeddySeagoon.
Yes the sda is the System rescue usb stick.
So i should try to set a rootwait to the kernel command line in grub.cfg?

Should i disinstall Grub2 and try with Refind?

NeddySeagoon · Posted: Sat Jul 16, 2016 8:11 pm Post subject:

beetterfly,

The problem is either with your kernel or the initrd init script not loading a module you need to make your eMMC device visible.

Grub is doing its thing as your kernel loads, starts and then panics.
The bootloader has finished then.

Boot SystemRescueCD, make sure you can see /dev/mmcblk0 and friends.
Run

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks NeddySeagoon, nice trick.i follow your instruction.
i get the list of loaded modules from Boot SystemRescueCD.
i rebooted the laptop, typed shell for the shell and iit appear busybox prompt.
i typed lsmod on busybox.:
it take my attention one point in that list:

NeddySeagoon · Posted: Sun Jul 17, 2016 9:28 am Post subject:

beetterfly,

You need at least

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

thanks a lot NeddySeagoon.I tried to compile again with genkernel config all....
i set new configuration. but still doesn't work... :evil:

i get the same situation. i hope i set everithing correct.

DONAHUE · Posted: Sun Jul 17, 2016 1:40 pm Post subject:

The problem may be genkernel itself. I emerged genkernel-next, ran genkernel all on the existing gentoo-sources which included a working /usr/src/linux/.config. genkernel ran oldconfig incorporating my existing settings (verified by running cd /usr/src/linux; make menuconfig). Upon rebooting I was confronted by the same kernel panic as beeterfly. A few years ago genkernel had a similar problem when it's default config included a hardware raid controller that failed. Suggest forget genkernel and go with a manual kernel. The manual kernel default config is advertised as supporting the sdio bus out of the box.
_________________
Defund the FCC.

NeddySeagoon · Posted: Sun Jul 17, 2016 2:03 pm Post subject:

beetterfly,

Post your kernel .config file as it is now.

I'm inclined to go with what DONAHUE suggested but then, I've never used genkernel so I'm biased.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks agains..

this is my /usr/scr/linux/.config

https://bpaste.net/show/049dfbdee947

Can i use this configuration for manual kernel operation?

NeddySeagoon · Posted: Sun Jul 17, 2016 3:19 pm Post subject:

beetterfly,

That looks almost correct. You have some debug options on. They are intended for developers working on the code in that area of the kernel.
They all generate lots of log spam and a few debug options interfere with correct operation of the kernel too.

You can't quite use that kernel configuration for a manual build. A normal manual build has everything needed to mount root built into bzImage, so that no initrd is required.
You will have some changes there.
You also need to turn off all the debug options.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

thanks NeddySeagoon,now i try a manual build.it'll be my first manual build experience.
I hope will be the solution.
Thanks a lot everybody for the suggest and informations.

NeddySeagoon · Posted: Sun Jul 17, 2016 4:06 pm Post subject:

beetterfly,

You don't need a lot to be set to <*>
The partitiions code, the root filesystem code and the hardware drivers to get at the root filesystem.
That's the absolute minimum.

After that everything can be modular. My 11 year old guide is still about right.
These days you nee a bigger pot of coffee and tho output of lsusb.

There is another 'get you going' route.
Take the kernel, modules and firmware from SystemRescueCD. You are allowed to do that, its all provided under one open licence or another.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Great guide...now i start to study it.
i known that one time it will be necessary the manual build.So it's time right now to start.
Probably i put a lot of [*] even on debug stuff that i don't need.

NeddySeagoon · Posted: Sun Jul 17, 2016 5:57 pm Post subject:

beetterfly,

The SystemRescueCD contains a kernel that boots your system.
Once you boot SystemRescueCD, (do not chroot) you can see some of it.

The some of it you can see you can copy to the same places in your install.
Thats
/lib/firmware ... that goes to /mnt/gentoo/lib/firmware
Its the firmware for devices supported by limux. Normally from the linux-firmware package.
The other piece is /lib/modules/`uname -r'/ that goes to /mnt/gentoo/lib/modules/`uname -r'/
Its the kernel modules provided by SystemRescueCD.

The kernel and initrd are a little harder to find. They are probably not visible inside /boot as they are not located on the SystemRescueCD root filesystem.
Your raw SystemRescueCD is on /dev/sda1 which you normally do not mount.
Do

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

NeddySeagoon thanks so much for the precious informations. I tryed for curiosity the SystemRescueCD kernel. it worked.

So i reistalled everithing, i compile in manual mode the kernel, following your advise and the printed lspci and lsmod.
But something i miss again in the kernel config: i still have the same error:
"Could not find the root block device in UUID=d5777................."
-Please specify another value or:
-press Enter for the same
type shell for a shell
type "q" to skip

this is my .config
[code]wgetpaste -t /mnt/gentoo/usr/src/linux/.config[code] [url] https://bpaste.net/show/1a406ecd0b64[/url]

my grub.cfg
[code]wgetpaste -t /mnt/gentoo/boot/grub/grub.cfg[/code] [url] https://bpaste.net/show/59836cb10a22[/url]

i'm really getting crazy.
One thing, could be not important. The disk's name is /dev/mmcblk0.
I see that if i insert an a memory stik in a card reader, it call /dev/mmcblk1. look like the same family disk.
In the busybox shell doesn't recognice any kind of disk. but if i insert an usb, i can see it.
So set in the kernel the Realtek card Reader.
But still doesn't work.I hope that i'll not trow away that laptop :twisted:

Thanks everibody in advance

NeddySeagoon · Posted: Tue Jul 19, 2016 9:11 pm Post subject:

beetterfly,

Since the SystemRescueCD kernel works, use that for now.

You can have several kernels installed at the same time and use the grub menu to choose between them.
Everyone makes a dud kernel from time to time and its good to fix it without doing the chroot dance :)

You can use the SystemRescueCD kernel to get you going, while you make your own.

I have a similar problem on by Raspberry Pi install. The kernel does not see /dev/mmcblk0 either.
Enough of my troubles. Maybe fixing one will fix the other too.

At the weekend, I will try to configure a kernel for you. I'll post the .config file, then you can build and test it.
It will not need an initrd.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks a lot NeddySeagoon, i'm such grateful for your interest. I learned a lot following your posts.
You acted like an older brother.
I'll wait an your kernel configuration.
Meanwhile i'll do other attemps. i hope to resolve it.
Thanks again

NeddySeagoon · Posted: Wed Jul 20, 2016 9:17 pm Post subject:

beetterfly,

I've read some reviews of the E11. Your storage might actually be a real NVMe device, even though in appears as an mmc card.
If so, you need <*> NVM Express block device and maybe
[*] SCSI emulation for NVMe device nodes.

Also add rootwait to the kernel command line, as we have seen an Intel NVMe drive be slow to get started.

You did have <M> NVM Express block device in your original kernel but the genkernel initrd init script does not load it.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

beetterfly · n00b Joined: 17 Jun 2016 Posts: 26

Thanks so much NeddySeagoon.
I compiled the kernel with NVM Express block device support and SCSI emulation for NVMe too.
i give again the grub mkconfig

NeddySeagoon · Posted: Thu Jul 21, 2016 7:12 pm Post subject:

beetterfly,

That looks like rootwait waiting for ever and /dev/mmcblk0p2 never appearing, so root is never mounted.
I have your .config half done.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.