This bug has been copied from bug #771624 and has been proposed to be backported to 6.3 z-stream (EUS).
Reproduced with qemu-kvm-0.12.1.2-2.295.el6.x86_64: [root@localhost ~]# /usr/libexec/qemu-kvm -serial unix:/tmp/u1,server,nowait -serial unix:/tmp/u2,server,nowait -serial unix:/tmp/u3,server,nowait isa irq 4 already assigned Verified on qemu-kvm-0.12.1.2-2.295.el6_3.1.x86_64: [root@localhost ~]# /usr/libexec/qemu-kvm -serial unix:/tmp/u1,server,nowait -serial unix:/tmp/u2,server,nowait -serial unix:/tmp/u3,server,nowait -serial unix:/tmp/u4,server,nowait VNC server running on `::1:5900' [root@localhost ~]# /usr/libexec/qemu-kvm -serial unix:/tmp/u1,server,nowait -serial unix:/tmp/u2,server,nowait -serial unix:/tmp/u3,server,nowait -serial unix:/tmp/u4,server,nowait -serial unix:/tmp/u5,server,nowait qemu: too many serial ports
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-1121.html