Re: [Qemu-discuss] qemu usage help

[Mike Lovell]

On 06/16/2012 12:39 AM, beyond.hack wrote:

thanks for your reply sir,
I removed the console=ttyS0,115200n8 from the command line still no change..

On Fri, Jun 15, 2012 at 11:45 PM, Mike Lovell <address@hidden> wrote:

On 06/14/2012 02:01 AM, beyond.hack wrote:

I am just starting out with qemu and confused with the execution of a command as it is giving one or other other..

$qemu-system-i386 -kernel <mykernelimage> -initrd <my initramfs> -append "root=/dev/hda1 console=ttyS0,115200n8 console=tty0" 

here I replaced /dev/hda1 with my /dev/sda5 (my root) still it is not executing ...

i think it actually is running. the kernel messages seem consistent with what the kernel would say during start up. it is missing the userspace output but that is because you specified "console=ttyS0" before "console=tty0." usually this results in all of the userspace messages getting written to the serial console and not to tty0. try changing the qemu window to the serial0 console by pressing ctrl-alt-3. there might be some information there.

if there isn't anything on the serial0 console, try removing the "console=ttyS0,115200n8" part from you -append.

as a side note, it might also be possible that your system isn't booting because on the command line you listed, you are not defining a virtual disk to use. so the guest may not have a hda or sda to mount a root filesystem from. from your screenshot it seems the kernel got past that part but it is incomplete output.

I too think that the system is not yet booting ..
can u please tell me how to specify the virtual disk image......but for what I am passing the -append root=/dev/sda5??????

re-adding the list as a cc

you can specify the virtual disk a number of ways. the easiest would probably be to add a '-hda /path/to/virtual/disk' to the command line. depending on how the linux kernel in the guest is configured, it might show up as /dev/hda or /dev/sda. if its from a recent linux distribution, it will probably show up as sda to the guest. you also could do '-drive file=/path/to/virtual/disk' which will have the same effect but is a more extensible way of specifying the disk. you could do '-drive file=/path/to/virtual/disk,if=virtio' if you wanted to have the guest see the disk as a virtio disk and in this case the guest would see the disk as /dev/vda. '-drive file=/path/to/virtual/disk,if=scsi' should always result in the disk showing up as /dev/sda and use a scsi interface. the man page for qemu-system-i386 should have many more details.

in the above examples, /path/to/virtual/disk should point to something the guest can use as a virtual disk. it should *not* point to the block device that holds your host's system. the details in your emails are a little ambiguous and it almost sounds like you are trying to have the guest use the same root filesystem as your host. this is not what you want. you should probably have a file somewhere that should act as a virtual disk somewhere.

hope that helps.

mike