Which file indicates that the kernel file is compressed using the bzImage method?

The file that indicates the kernel file is compressed using the bzImage method is vmlinuz. The naming convention for this file follows the syntax where the 'z' in "vmlinuz" signifies that the kernel is compressed. The bzImage format allows for a larger kernel image, supporting more RAM and additional features not feasible in the standard image format, which is generally uncompressed.

Vmlinux typically refers to the uncompressed kernel executable that is built during the compilation process. Linux.img is not commonly used in standard Linux distributions to denote a compressed kernel, and kernel.gz usually indicates a kernel file that is compressed using gzip, which is a different method from bzImage. Therefore, vmlinuz is the correct file name indicating that the kernel is indeed compressed using the bzImage method.