Re: [Qemu-discuss] what's wrong with mey qemu-kvm

[Mike Lovell]

On 08/26/2012 08:39 AM, lei yang wrote:
> It seems initramfs-2.6.32-279.el6.x86_64.img don't contains the
> rootfs, what is in it?
>
> if use virtual disk, where could I get the rootfs file such as /lib
> /bin /sbin /user ....?

correct. the file initramfs-2.6.32-279.el6.x86_64.img does not contain 
the rootfs for the booted system. it contains files for a tmpfs 
filesystem that gets loaded during the boot process. this filesystems 
contains some kernel modules and a limited set of system utilities. 
these utilities are responsible for getting the real rootfs mounted and 
then changing control to the new rootfs. discussing this topic could 
make this email very very very long. http://en.wikipedia.org/wiki/Initrd 
has some good details about how an initrd/initramfs works and googling 
for initrd or initramfs will provide a good deal of other places to 
learn about it.

as for where to get the rootfs for a new virtual disk, there are a 
couple ways. what is easiest for most people is to go through the 
regular OS installation process. if you add a '-cdrom /path/to/rhel/dvd' 
option to your qemu command, then qemu can boot off of that and go 
through the regular installation process. you'll need to replace 
/path/to/rhel/dvd with the location of your cd/dvd drive or the location 
of an installation iso.

mike