[SOLVED] Unable to mount root fs

7Jean7 · 01-07-2020, 12:46 AM

I get kernel panic from my freshly compiled linux kernel booting from USB key (like here Unable to mount root fs)

error : unable to mount root fs on unknown-block(0,0)
kernel version : 5.5-rc5
bootloader : none (EFI stub)
built-in kernel command line : root=PARTUUID=xx1-xx1-xx1-1xx
kernel supports root's filesystem : f2fs
kernel is moduleless

Solutions tried/tested

checked PARTUUID of the root device 3 times
kernel do load my sata ssd with proper PARTUUID
kernel doesn't mount other USB drive
BLK_DEV=y, BLK_DEV_SD=y, USB_STORAGE=y, ...
tried with UUID and /dev/sda2 same result

It seems to be a USB problem something wrong in kernel configuration ?

smallpond · 01-07-2020, 07:56 AM

Presumably CONFIG_F2FS_FS=y.

On the kernel command line, add "ignore_loglevel" to print all log messages to the console from early in boot.

7Jean7 · 01-07-2020, 08:46 AM

that was number 1. in solutions (1. kernel supports root's filesystem)
and rechecked by 4. in solutions (cause my SSD is also f2fs)

7Jean7 · 01-07-2020, 10:09 PM

Ok it turns to be a slow USB subsystem.
rootwait added to the kernel command line fixed that

all the credit goes to NeddySeagoon from Gentoo Forum
link to the post Unable to mount root fs