I have a freshly installed 18.04 box. Updates were installed and rebooted. It's running kernel 4.15.0-74 without an issue:
root@restore:~# uname -a
Linux restore 4.15.0-74-generic #84-Ubuntu SMP Thu Dec 19 08:06:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
But due to incompatibility with a third party vendor I had to downgrade the kernel to 4.15.0-72. So.. I installed the package and rebooted into that kernel.
However.. I'm thrown back to initramfs immediately, after which it tells me:
Gave up waiting for root file system device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Missing moduiles (cat /proc/modules; ls /dev)
ALERT! UUID=2e897a65-bbcc-426d-a72e-8aca96121c80 does not exist. Dropping to a shell!
The UUID is correct:
root@restore:~# blkid /dev/sda2
/dev/sda2: UUID="2e897a65-bbcc-426d-a72e-8aca96121c80" TYPE="ext4" PARTUUID="22caffaa-6efd-406b-acba-dbd8a53c72d1"
I've added a rootdelay=60 to the grub config, ran update-grub again, no luck.
root@restore:~# cat /etc/default/grub
GRUB_DEFAULT=0
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="noresume rootdelay=60"
GRUB_CMDLINE_LINUX="netcfg/do_not_use_netplan=true"
GRUB_TERMINAL=console
I also regenerated the initrd and run update-grub again. No luck.
root@restore:~# update-initramfs -c -k 4.15.0-72-generic
update-initramfs: Generating /boot/initrd.img-4.15.0-72-generic
More verbose output can be found: https://pastebin.com/8PEwkh05
And contents of fstab as requested below:
root@restore:~# cat /etc/fstab
UUID=2e897a65-bbcc-426d-a72e-8aca96121c80 / ext4 defaults 0 0
/swap.img none swap sw 0 0
Am I missing something blindingly obvious here? Hardware is a QEMU VM. I'm able to reproduce this on each VM I build from the install ISO.
update-initramfs -u -v -k 4.15.0-72-generic
much output andcat /etc/fstab
.