I tried running qemu-system-x86_64 -help" command manually. But it seems that it work normally. Here is the output. Kindly guide me. spanhal1@seclab2:/usr/bin$ qemu-system-x86_64 -help QEMU emulator version 1.2.0 (qemu-kvm-1.2.0), Copyright (c) 2003-2008 Fabrice Bellard usage: qemu-system-x86_64 [options] [disk_image] 'disk_image' is a raw hard disk image for IDE hard disk 0 Standard options: -h or -help display this help and exit -version display version information and exit -machine [type=]name[,prop[=value][,... ]] selects emulated machine (-machine ? for list) property accel=accel1[:accel2[:...]] selects accelerator supported accelerators are kvm, xen, tcg (default: tcg) kernel_irqchip=on|off controls accelerated irqchip support kvm_shadow_mem=size of KVM shadow MMU dump-guest-core=on|off include guest memory in a core dump (default=on) -cpu cpu select CPU (-cpu ? for list) -smp n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets] set the number of CPUs to 'n' [default=1] maxcpus= maximum number of total cpus, including offline CPUs for hotplug, etc cores= number of CPU cores on one socket threads= number of threads on one CPU core sockets= number of discrete sockets in the system -numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node] -fda/-fdb file use 'file' as floppy disk 0/1 image -hda/-hdb file use 'file' as IDE hard disk 0/1 image -hdc/-hdd file use 'file' as IDE hard disk 2/3 image -cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master) -drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i] [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off] [,cache=writethrough|writeback|none|directsync|unsafe][,format=f] [,serial=s][,addr=A][,id=name][,aio=threads|native] [,readonly=on|off][,copy-on-read=on|off] [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]][[,iops=i]|[[,iops_rd=r][,iops_wr=w]] use 'file' as a drive image -set group.id.arg=value set <arg> parameter for item <id> of type <group> i.e. -set drive.$id.file=/path/to/image -global driver.prop=value set a global default for a driver property -mtdblock file use 'file' as on-board Flash memory image -sd file use 'file' as SecureDigital card image -pflash file use 'file' as a parallel flash image -boot [order=drives][,once=drives][,menu=on|off] [,splash=sp_name][,splash-time=sp_time] 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n) 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on 'sp_time': the period that splash picture last if menu=on, unit is ms -snapshot write to temporary files instead of disk image files -m megs set virtual RAM size to megs MB [default=128] -mem-path FILE provide backing storage for guest RAM -mem-prealloc preallocate guest memory (use with -mem-path) -k language use keyboard layout (for example 'fr' for French) -audio-help print list of audio drivers and their options -soundhw c1,... enable audio support and only specified sound cards (comma separated list) use -soundhw ? to get the list of supported cards use -soundhw all to enable all of them -balloon none disable balloon device -balloon virtio[,addr=str] enable virtio balloon device (default) -usb enable the USB driver (will be the default soon) -usbdevice name add the host or guest USB device 'name' -device driver[,prop[=value][,...]] add device (based on driver) prop=value,... sets driver properties use -device ? to print all possible drivers use -device driver,? to print all possible properties File system options: -fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}] [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd] Virtual File system pass-through options: -virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none] [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd] -virtfs_synth Create synthetic file system image -name string1[,process=string2] set the name of the guest string1 sets the window title and string2 the process name (on Linux) -uuid %08x-%04x-%04x-%04x-%012x specify machine UUID Display options: -display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off] [,window_close=on|off]|curses|none| vnc=<display>[,<optargs>] select display type -nographic disable graphical output and redirect serial I/Os to console -curses use a curses/ncurses interface instead of SDL -no-frame open SDL window without a frame and window decorations -alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt) -ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt) -no-quit disable SDL window close capability -sdl enable SDL -spice <args> enable spice -portrait rotate graphical output 90 deg left (only PXA LCD) -rotate <deg> rotate graphical output some deg left (only PXA LCD) -vga [std|cirrus|vmware|qxl|xenfb|none] select video card type -full-screen start in full screen -vnc display start a VNC server on display i386 target only: -win2k-hack use it when installing Windows 2000 to avoid a disk full bug -no-fd-bootchk disable boot signature checking for floppy disks -no-acpi disable ACPI -no-hpet disable HPET -acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n][,asl_compiler_id=str][,asl_compiler_rev=n][,{data|file}=file1[:file2]...] ACPI table description -smbios file=binary load SMBIOS entry from binary file -smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d] specify SMBIOS type 0 fields -smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str] [,uuid=uuid][,sku=str][,family=str] specify SMBIOS type 1 fields Network options: -net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v] create a new Network Interface Card and connect it to VLAN 'n' -net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off] [,hostname=host][,dhcpstart=addr][,dns=addr][,tftp=dir][,bootfile=f] [,hostfwd=rule][,guestfwd=rule][,smb=dir[,smbserver=addr]] connect the user mode network stack to VLAN 'n', configure its DHCP server and enabled optional services -net tap[,vlan=n][,name=str][,fd=h][,ifname=name][,script=file][,downscript=dfile][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostforce=on|off] connect the host TAP network interface to VLAN 'n' use network scripts 'file' (default=/etc/qemu-ifup) to configure it and 'dfile' (default=/etc/qemu-ifdown) to deconfigure it use '[down]script=no' to disable script execution use network helper 'helper' (default=/usr/local/libexec/qemu-bridge-helper) to configure it use 'fd=h' to connect to an already opened TAP interface use 'sndbuf=nbytes' to limit the size of the send buffer (the default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576') use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition use vhost=on to enable experimental in kernel accelerator (only has effect for virtio guests which use MSIX) use vhostforce=on to force vhost on for non-MSIX virtio guests use 'vhostfd=h' to connect to an already opened vhost net device -net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper] connects a host TAP network interface to a host bridge device 'br' (default=br0) using the program 'helper' (default=/usr/local/libexec/qemu-bridge-helper) -net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port] connect the vlan 'n' to another VLAN using a socket connection -net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]] connect the vlan 'n' to multicast maddr and port use 'localaddr=addr' to specify the host address to send packets from -net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port] connect the vlan 'n' to another VLAN using an UDP tunnel -net dump[,vlan=n][,file=f][,len=n] dump traffic on vlan 'n' to file 'f' (max n bytes per packet) -net none use it alone to have zero network devices. If no -net option is provided, the default is '-net nic -net user' -netdev [user|tap|bridge|socket],id=str[,option][,option][,...] Character device options: -chardev null,id=id[,mux=on|off] -chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay] [,server][,nowait][,telnet][,mux=on|off] (tcp) -chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix) -chardev udp,id=id[,host=host],port=port[,localaddr=localaddr] [,localport=localport][,ipv4][,ipv6][,mux=on|off] -chardev msmouse,id=id[,mux=on|off] -chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]] [,mux=on|off] -chardev file,id=id,path=path[,mux=on|off] -chardev pipe,id=id,path=path[,mux=on|off] -chardev pty,id=id[,mux=on|off] -chardev stdio,id=id[,mux=on|off][,signal=on|off] -chardev tty,id=id,path=path[,mux=on|off] -chardev parport,id=id,path=path[,mux=on|off] -iscsi [user=user][,password=password] [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE [,initiator-name=iqn] iSCSI session parameters Bluetooth(R) options: -bt hci,null dumb bluetooth HCI - doesn't respond to commands -bt hci,host[:id] use host's HCI with the given name -bt hci[,vlan=n] emulate a standard HCI in virtual scatternet 'n' -bt vhci[,vlan=n] add host computer to virtual scatternet 'n' using VHCI -bt device:dev[,vlan=n] emulate a bluetooth device 'dev' in scatternet 'n' Linux/Multiboot boot specific: -kernel bzImage use 'bzImage' as kernel image -append cmdline use 'cmdline' as kernel command line -initrd file use 'file' as initial ram disk -dtb file use 'file' as device tree image Debug/Expert options: -serial dev redirect the serial port to char device 'dev' -parallel dev redirect the parallel port to char device 'dev' -monitor dev redirect the monitor to char device 'dev' -qmp dev like -monitor but opens in 'control' mode -mon chardev=[name][,mode=readline|control][,default] -debugcon dev redirect the debug console to char device 'dev' -pidfile file write PID to 'file' -singlestep always run in singlestep mode -S freeze CPU at startup (use 'c' to start execution) -gdb dev wait for gdb connection on 'dev' -s shorthand for -gdb tcp::1234 -d item1,... output log to /tmp/qemu.log (use -d ? for a list of log items) -D logfile output log to logfile (instead of the default /tmp/qemu.log) -hdachs c,h,s[,t] force hard disk 0 physical geometry and the optional BIOS translation (t=none or lba) (usually QEMU can guess them) -L path set the directory for the BIOS, VGA BIOS and keymaps -bios file set the filename for the BIOS -enable-kvm enable KVM full virtualization support -xen-domid id specify xen guest domain id -xen-create create domain using xen hypercalls, bypassing xend warning: should not be used when xend is in use -xen-attach attach to existing xen domain xend will use this when starting QEMU -no-reboot exit instead of rebooting -no-shutdown stop before shutdown -loadvm [tag|id] start right away with a saved state (loadvm in monitor) -daemonize daemonize QEMU after initializing -option-rom rom load a file, rom, into the option ROM space -clock force the use of the given methods for timer alarm. To see what timers are available use -clock ? -rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew] set the RTC base and clock, enable drift fix for clock ticks (x86 only) -icount [N|auto] enable virtual instruction counter with 2^N clock ticks per instruction -watchdog i6300esb|ib700 enable virtual hardware watchdog [default=none] -watchdog-action reset|shutdown|poweroff|pause|debug|none action when watchdog fires [default=reset] -echr chr set terminal escape character instead of ctrl-a -virtioconsole c set virtio console -show-cursor show cursor -tb-size n set TB size -incoming p prepare for incoming migration, listen on port p -nodefaults don't create default devices -chroot dir chroot to dir just before starting the VM -runas user change to user id user just before starting the VM -sandbox <arg> Enable seccomp mode 2 system call filter (default 'off'). -readconfig <file> -writeconfig <file> read/write config file -nodefconfig do not load default config files at startup -no-user-config do not load user-provided config files at startup -trace [events=<file>][,file=<file>] specify tracing options -qtest CHR specify tracing options -qtest-log LOG specify tracing options -enable-fips enable FIPS 140-2 compliance -no-kvm disable KVM hardware virtualization -no-kvm-irqchip disable KVM kernel mode PIC/IOAPIC/LAPIC -no-kvm-pit disable KVM kernel mode PIT -no-kvm-pit-reinjection disable KVM kernel mode PIT interrupt reinjection During emulation, the following keys are useful: ctrl-alt-f toggle full screen ctrl-alt-n switch to virtual console 'n' ctrl-alt toggle mouse and keyboard grab When using -nographic, press 'ctrl-a h' to get some help. spanhal1@seclab2:/usr/bin$ Thanks, Sanket On Fri, Jun 13, 2014 at 3:47 AM, Claudio Bley <cbley(a)av-test.de&gt; wrote:

Hi, Yes, I have called the exact program and the command works smoothly. I am using Ubuntu12.04. Currently, I am re-installing everything from the beginning and will let you know if problem is solved else will look for debug logging of libvirt. Thanks for reply and help. Thanks, Sanket On Wed, Jun 18, 2014 at 3:25 AM, Claudio Bley <cbley(a)av-test.de&gt; wrote: