vmlinuz?
I don't know the meaning of this file.
who can explain it?

When you start the computer, a "boot loader" runs to let you choose which system you want to start. If you choose Linux, the boot loader has to locate the kernel-image that needs to be brought into memory. That's "vmlinuz."

Now... why the "z?" Well, that refers obscurely to the fact that the kernel-image is compressed. The kernel-image file is first loaded into memory, then it automagically un-compresses itself.

Once the kernel-image is loaded into memory (and uncompressed), the boot loader hands-over control to it.

thanks for your reply!
when I installed virtual linux in XP,I met two files---vmlinuz &initrd.img.
what's the meaning of initrd.img?
i always think it is the bootloader in linux.
Is it true? why ? Who can explain it?
thanks!

initrd.img is an image that is loaded into RAM during the boot process. It is not always used. Details: http://www.google.com/search?q=initr...L_enUS177US235

The bootloader is code stored in the MBR and other drive sectors, and is responsible for finding and loading the kernel.

Here's the skinny about initrd...

When a "distro" writer is putting together their system, the thing they've got to figure-out is just how to make their distro "run on anything." (And, oh yeah, "make it look easy.")

So... they might need to be able to do things before Linux, itself, actually starts booting. They might need to detect hardware and load some device-drivers, for example, just so that Linux will be able to locate and access "this particular hard-drive." And so it goes.

So... what the kernel folks came up with is, believe it or not, "a virtual 'boot floppy.'" It's a tiny, absolutely-stripped-down environment that can run before Linux itself does, in a "John the Baptist sort of way," to "prepare the way for the Linux."

That's initrd. It's the one that puts up that very nice-looking splash screen, by the way, that you see during most of the time that a typical Linux-distro boots. (Wanna get technical? OS/X and Windows do it the same way, too.)