mkinitrd - it is used to create an image file that is loaded into the RAM disk during the boot process

syntax $ sudo mkinitrd [options] <initrd-image> <kernel-version>

$ sudo apt install dracut-core

To create a new image file $ sudo mkinitrd -f /boot/initrd.img-5.11.0-051100-generic 5.11.0-051100-generic

To display verbose output during the creation of the image file $ sudo mkinitrd -v -f /boot/initrd.img-5.11.0-051100-generic 5.11.0-051100-generic

regards, T.Dhanasekar