Hi, I am using libguestfs 1.12.0 and I am facing a problem with it . I am using guestfs python bindings to "launch" a vdi image file . It works fine except immediately after a VM is stopped(which uses the same vdi file) i.e in normal conditions launch command works but when a vm (which uses the same vdi file) is started - stopped , a call to "launch" command hangs the terminal. Please help . this is the output of the libguestfs_debug : libguestfs: new guestfs handle 0x7f0e3007dee0 libguestfs: trace: set_autosync true libguestfs: trace: set_autosync = 0 libguestfs: trace: launch libguestfs: [00000ms] febootstrap-supermin-helper --verbose -f checksum '/usr/lib/guestfs/supermin.d' x86_64 supermin helper [00000ms] whitelist = (not specified), host_cpu = x86_64, kernel = (null), initrd = (null), appliance = (null) supermin helper [00000ms] inputs[0] = /usr/lib/guestfs/supermin.d checking modpath /lib/modules/2.6.38-8-generic is a directory picked vmlinuz-2.6.38-8-generic because modpath /lib/modules/2.6.38-8-generic exists supermin helper [00000ms] finished creating kernel supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/base.img supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/daemon.img supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/hostfiles supermin helper [00024ms] visiting /usr/lib/guestfs/supermin.d/init.img supermin helper [00125ms] finished creating appliance libguestfs: [00129ms] begin testing qemu features libguestfs: [00144ms] finished testing qemu features libguestfs: is_openable: /dev/kvm: No such file or directory libguestfs: accept_from_daemon: 0x7f0e3007dee0 g->state = 1 libguestfs: [00146ms] /usr/bin/kvm \ -drive 'file=/home/yeswanth/VirtualBox VMs/damnit/damnit.vdi,cache=off,if=virtio' \ -nodefconfig \ -nodefaults \ -nographic \ -m 500 \ -no-reboot \ -no-hpet \ -device virtio-serial \ -serial stdio \ -chardev socket,path=/tmp/libguestfszoC739/guestfsd.sock,id=channel0 \ -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \ -kernel /var/tmp/.guestfs-1000/kernel.30876 \ -initrd /var/tmp/.guestfs-1000/initrd.30876 \ -append 'panic=1 console=ttyS0 udevtimeout=300 noapic acpi=off printk.time=1 cgroup_disable=memory selinux=0 guestfs_verbose=1 TERM=xterm ' \ -drive file=/var/tmp/.guestfs-1000/root.30876,snapshot=on,if=virtio,cache=unsafe open /dev/kvm: No such file or directory Could not initialize KVM, will disable KVM support [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Linux version 2.6.38-8-generic (buildd@allspice) (gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu3) ) #42-Ubuntu SMP Mon Apr 11 03:31:24 UTC 2011 (Ubuntu 2.6.38-8.42-generic 2.6.38.2) [ 0.000000] Command line: panic=1 console=ttyS0 udevtimeout=300 noapic acpi=off printk.time=1 cgroup_disable=memory selinux=0 guestfs_verbose=1 TERM=xterm [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009bc00 (usable) [ 0.000000] BIOS-e820: 000000000009bc00 - 00000000000a0000 (reserved) [ 0.000000] BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) [ 0.000000] BIOS-e820: 0000000000100000 - 000000001f3fd000 (usable) [ 0.000000] BIOS-e820: 000000001f3fd000 - 000000001f400000 (reserved) [ 0.000000] BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved) [ 0.000000] NX (Execute Disable) protection: active [ 0.000000] DMI 2.4 present. [ 0.000000] No AGP bridge found [ 0.000000] last_pfn = 0x1f3fd max_arch_pfn = 0x400000000 [ 0.000000] x86 PAT enabled: cpu 0, old 0x0, new 0x7010600070106 [ 0.000000] found SMP MP-table at [ffff8800000fd790] fd790 [ 0.000000] init_memory_mapping: 0000000000000000-000000001f3fd000 [ 0.000000] RAMDISK: 1f2df000 - 1f3f0000 [ 0.000000] No NUMA configuration found [ 0.000000] Faking a node at 0000000000000000-000000001f3fd000 [ 0.000000] Initmem setup node 0 0000000000000000-000000001f3fd000 [ 0.000000] NODE_DATA [000000001f3f5000 - 000000001f3f9fff] [ 0.000000] Zone PFN ranges: [ 0.000000] DMA 0x00000010 -> 0x00001000 [ 0.000000] DMA32 0x00001000 -> 0x00100000 [ 0.000000] Normal empty [ 0.000000] Movable zone start PFN for each node [ 0.000000] early_node_map[2] active PFN ranges [ 0.000000] 0: 0x00000010 -> 0x0000009b [ 0.000000] 0: 0x00000100 -> 0x0001f3fd [ 0.000000] SFI: Simple Firmware Interface v0.81 http://simplefirmware.org [ 0.000000] Intel MultiProcessor Specification v1.4 [ 0.000000] MPTABLE: OEM ID: BOCHSCPU [ 0.000000] MPTABLE: Product ID: 0.1 [ 0.000000] MPTABLE: APIC at: 0xFEE00000 [ 0.000000] Processor #0 (Bootup-CPU) [ 0.000000] IOAPIC[0]: apic_id 1, version 17, address 0xfec00000, GSI 0-23 [ 0.000000] Processors: 1 [ 0.000000] SMP: Allowing 1 CPUs, 0 hotplug CPUs [ 0.000000] PM: Registered nosave memory: 000000000009b000 - 000000000009c000 [ 0.000000] PM: Registered nosave memory: 000000000009c000 - 00000000000a0000 [ 0.000000] PM: Registered nosave memory: 00000000000a0000 - 00000000000f0000 [ 0.000000] PM: Registered nosave memory: 00000000000f0000 - 0000000000100000 [ 0.000000] Allocating PCI resources starting at 1f400000 (gap: 1f400000:e0bc0000) [ 0.000000] Booting paravirtualized kernel on bare hardware [ 0.000000] setup_percpu: NR_CPUS:256 nr_cpumask_bits:256 nr_cpu_ids:1 nr_node_ids:1 [ 0.000000] PERCPU: Embedded 28 pages/cpu @ffff88001f000000 s84416 r8192 d22080 u2097152 [ 0.000000] Built 1 zonelists in Node order, mobility grouping on. Total pages: 126124 [ 0.000000] Policy zone: DMA32 [ 0.000000] Kernel command line: panic=1 console=ttyS0 udevtimeout=300 noapic acpi=off printk.time=1 cgroup_disable=memory selinux=0 guestfs_verbose=1 TERM=xterm [ 0.000000] Disabling memory control group subsystem [ 0.000000] PID hash table entries: 2048 (order: 2, 16384 bytes) [ 0.000000] Checking aperture... [ 0.000000] No AGP bridge found [ 0.000000] Memory: 488716k/511988k available (5940k kernel code, 468k absent, 22804k reserved, 5017k data, 956k init) [ 0.000000] SLUB: Genslabs=15, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 [ 0.000000] Hierarchical RCU implementation. [ 0.000000] RCU dyntick-idle grace-period acceleration is enabled. [ 0.000000] RCU-based detection of stalled CPUs is disabled. [ 0.000000] NR_IRQS:16640 nr_irqs:256 16 [ 0.000000] Console: colour dummy device 80x25 [ 0.000000] console [ttyS0] enabled [ 0.000000] Fast TSC calibration using PIT [ 0.000000] Detected 2526.022 MHz processor. [ 0.000472] Calibrating delay loop (skipped), value calculated using timer frequency.. 5052.04 BogoMIPS (lpj=25260220) [ 0.001006] pid_max: default: 32768 minimum: 301 [ 0.001935] Security Framework initialized [ 0.004110] AppArmor: AppArmor initialized [ 0.004301] Yama: becoming mindful. [ 0.008970] Dentry cache hash table entries: 65536 (order: 7, 524288 bytes) [ 0.010000] Inode-cache hash table entries: 32768 (order: 6, 262144 bytes) [ 0.010000] Mount-cache hash table entries: 256 [ 0.010000] Initializing cgroup subsys ns [ 0.010000] ns_cgroup deprecated: consider using the 'clone_children' flag without the ns_cgroup. [ 0.010000] Initializing cgroup subsys cpuacct [ 0.010000] Initializing cgroup subsys memory [ 0.010000] Initializing cgroup subsys devices [ 0.010000] Initializing cgroup subsys freezer [ 0.010000] Initializing cgroup subsys net_cls [ 0.010000] Initializing cgroup subsys blkio [ 0.010000] mce: CPU supports 10 MCE banks [ 0.010000] SMP alternatives: switching to UP code [ 0.010000] Freeing SMP alternatives: 20k freed [ 0.010000] ftrace: allocating 24314 entries in 96 pages [ 0.010000] Setting APIC routing to flat [ 0.010000] CPU0: AMD QEMU Virtual CPU version 0.14.0 stepping 03 The terminal hangs after this output . -- Cheers, Yeswanth