Mine

satan@krystal:~$ qemu -hda imagen.img -cdrom /home/satan/Desktop/xubuntu-6.10-desktop-i386.iso -boot c -m 256
Could not configure '/dev/rtc' to have a 1024 Hz timer. This is not a fatal
error, but for better emulation accuracy either use a 2.6 host Linux kernel or
type 'echo 1024 > /proc/sys/dev/rtc/max-user-freq' as root.
satan@krystal:~$ sudo echo 1024 > /proc/sys/dev/rtc/max-user-freq
bash: /proc/sys/dev/rtc/max-user-freq: Permiso denegado
satan@krystal:~$