[6.10.3] Kernel panic – Unable to mount root fs on unknown-block(0,0)

Do you know the previous release you were running?

 

If it's one of those you downgrade to and now it doesn't work suggests it's some flash/install issue.

It was either 6.9.2 or 6.10.0/6.10.1.

 

6.10.1 is the only version I did not verify. Will do it right now.

 

---

 

6.10.1 - Same issue.

6.10.0 - Additional error information displayed.

 

scsi 0:0:0:0: Direct-Access Generic Flash Disk 8.01 PQ: 0 ANSI: 6
sd 0:0:0:0: Attached scsi generic sg0 type 0
sd 0:0:0:0: [sda] Attached SCSI removable disk
List of all partitions:
0800	61849600 sda
 driver: sd
  0801	61848576 sda1 00000000-01

No filesystem could mount root, tried:
 squashfs
 vfat
 msdos
 iso9660
 fuseblk
 udf
 btrfs

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown0block(8,0)

 

Still doesn't boot though...

Edited June 15, 2022 by topscoder
wrong version number

Just tried to create USB stick on Windows (used macOS before). Same issue.

 

Beats me.. anyone with insights or help?

Also not booting with a previous known good release confirms it's not a release problem, try creating the flash drive manually with diskpart:

 

https://lime-technology.com/forums/topic/49992-update-from-619-to-62-rc5-need-help/?tab=comments#comment-492238

 

 

 

 

I directly tried it using Windows 10 (native).

 

- diskpart

- clean

- format fat32

- copy backup files to usb stick

- run make_bootable.bat as admin

(all of the above went ok without errors)

 

Booting...

/dev/root: Can't open blockdev

VFS: Cannot open root device "sda" or unknown-block(0,0): error -6

 

Also tried formatting using balenaEtcher (FAT32), but also without luck. 16GB USB Stick isn't a problem is it?

Edited June 15, 2022 by topscoder

1 hour ago, topscoder said:

16GB USB Stick isn't a problem is it?

No, but I would try with a couple different flash drives if you have some lying around, you don't need a key, just to see if it boots.

Looks like I am running into a similar issue doing the same thing. Just upgrading to 6.10.3 from 6.10.2. Any luck with yours? I have not tried anything yet.

Just an update from me: It seems like the My Servers plugin received a backup from my server after it finished upgrading to 6.10.3 and before rebooting. I was able to restore my flash drive from that backup and now I am booted up and running on 6.10.3.

9 hours ago, Merskies said:

Just an update from me: It seems like the My Servers plugin received a backup from my server after it finished upgrading to 6.10.3 and before rebooting. I was able to restore my flash drive from that backup and now I am booted up and running on 6.10.3.

Thanks for you update. Unfortunately "My Servers" states: "Flash backup unavailable"

12 hours ago, JorgeB said:

No, but I would try with a couple different flash drives if you have some lying around, you don't need a key, just to see if it boots.

Thanks for your tip. I've spent multiple hours fiddling around and at least got a step further.

 

I've found out adding 'debug' to the append line in syslinux.cfg, the boot process prints some more info. Which is helpful in my case.

 

I added 'root=/dev/sda1' to syslinux.cfg and found out the drive is found and is mounted during boot.

 

[sda] Attached SCSI removable disk
VFS: Mounted root (vfat filesystem) readonly on device 8:1.
devtmpfs: error mounting -2
rodata_tests: all tests were successful

Run /sbin/init as init process
  with arguments:
    /sbin/init
  with environment:
    HOME=/
    TERM=linux
    BOOT_IMAGE=/bzimage

... same for /etc/init, /bin/init, /bin/sh ...

Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance.

 

At least it tells me it *found* the usb disk. It mounted the device readonly and throws an error 'devtmpfs: error mounting'. To me it's unclear if devtmpfs related directly to failed mounting of the usb disk.

 

'No working init found'; I've read the documentation at https://www.kernel.org/doc/Documentation/admin-guide/init.rst which makes me believe the issue is either;

1) disk is available in boot process, but root FS cannot be mount (due to partition failure? /dev/sda1 isn't pointing to the right partition maybe?)

2) init binary doesn't exit on rootfs. I've tried to mount / open / inspect and bzcat bzimage, bzroot etc, but couldn't find a hint.

3) Binary cannot be loaded due to either architecture mismatch (i386 cs x86_64)

OR maybe the current shipped kernel dropped driver(s) / support for the hardware in my Mac Mini Server??

Didn't notice this before:

Hardware name: Apple Inc. Macmini5,3

It's notoriously hard to get Unraid booting on Apple hardware, you can try but it might be a lost cause to get that working reliably.

That's a bummer... worked like a charm for a long time.

 

Can you maybe point me in the right direction what I need to do to move to a new machine without losing data? Never looked at alternative hardware, but would appreciate advice

49 minutes ago, topscoder said:

Can you maybe point me in the right direction what I need to do to move to a new machine without losing data?

Usually you just need to move all the devices and the flash drive to the new hardware, exception to that is when RAID controllers and/or some USB enclosures are being used.

I just had this same issue trying to update from 6.10.2 to 6.10.3.

 

After reading this forum thread I decided I would try to use a backup of my USB from CA Backup/Restore Appdata that is stored on a Synology NAS. Once I plugged the USB into my computer I noticed a "previous" folder though. I then made another backup of the current USB (into a separate folder, JIC) to the NAS and then copied everything from "previous" to the root of the USB replacing all files.  Unraid is now running.

Edited June 18, 2022 by LogicalMadness
Misspelled

Same issue here upgrading from 6.10.2 to 6.10.3 - had to downgrade as I had the same error the OP is describing

Guess we just wait until another update comes out?