Linux uses cpio to decompress initrd. img

In kernel 2.6, initrd. IMG adopts cpio compression. It is no longer in the ext2 format used by kernel 2.4 and cannot be mounted using Mount-o loop. You need to use gunzip to decompress the package, and then use cpio to decompress the package.
CP/boot/initrd-***. IMG initrd.img.gz
Gunzip initrd.img.gz
Mkdir initrd
MV initrd. IMG initrd
CD initrd
Cpio-ivmd ../initrd. New. img
Gzip ../initrd. New. img
Copy the name to the/boot directory, and then restart it to observe the modified effect. Boot fails after restart. This is because the generated initrd. IMG is incorrect. The solution is as follows:
Generate initrd
Find. | cpio-o-h NEWC| Gzip>/mnt/sda1/boot/initrd. img-2.6.18-4-686
(Note:-h newc is required. Otherwise, the kernel will consider it as ramdisk rather than initramfs.)