VFS: Cannot open root device - Dell Workstation bug workaround

Problem

Some Dell Presision workstations like T3600 cannot boot kernel when initrd image file is bigger than 123MB (caused by the size of DKMS modules like nvidia):

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

Workaround

1. Boot different kernel and check if initrd image file is too big: ll /boot/initrd.img-*
2. Edit /etc/initramfs-tools/initramfs.conf. Set MODULES=dep (instead of most) and COMPRESS=xz (instead of zstd).
3. Check new initrd image size: ll /boot/initrd.img-*.
4. Update initramfs: sudo update-initramfs -u -k X.XX.X-XX-generic (replace kernel version number)

Comments

[zhang qingli]

great job! it works!