XEN:: How to reset root password in guest vm

:: How to reset root password in guest vm
+ Find info for guest disk file

xm list
cat /etc/xen/guest_name.conf
# you will see like this
disk = ["phy:/dev/xen_vol1/vs1001,sda1,w"]

+ mounting disk file and reset the root password

mount -o loop /dev/xen_vol1/vs1001 /mnt
chroot /mnt
mount -o remount,rw /
passwd
mount -o remount,ro /
exit

+ unmounting the disk

umount /mnt

+ reboot the guest vm

xm reboot guest_name