Update initramfs on Linux

Ubuntu

For Ubuntu,

1. dpkg-reconfigure the relevant linux-image package.
   1. This runs depmod if dkms has a module to install.
   2. This always runs update-initramfs and update-grub.
2. Use the following commands as needed.

depmod -a $(uname -r) # if this kernel's modules changed
update-initramfs -u -k all # updates existing kernels' initramfs
update-grub # only if have made changes to /etc/default/grub as well

References

• /var/lib/dpkg/info/linux-image-$(uname -r).postinst
• /etc/kernel/postinst.d/*

RHEL 10

depmod -a $(uname -r) # if this kernel's modules changed
dracut -fv /boot/initramfs-$(uname -r).img $(uname -r)