OK.  So now I am trying with a 2.6.38 kernel.  Surprising result: some confusion about ext2 root filesystem.  I can confirm the /var/tmp/.guestfs has a root file that is a valid ext2 file system.  

libguestfs: new guestfs handle 0x22df410
===== Test starts here =====
LIBGUESTFS_DEBUG=1
library version: 1.12.3
guestfs_get_append: (null)
guestfs_get_attach_method: appliance
guestfs_get_autosync: 1
guestfs_get_direct: 0
guestfs_get_memsize: 500
guestfs_get_network: 0
guestfs_get_path: /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs
guestfs_get_pgroup: 0
guestfs_get_qemu: /home/dek/sw/qemu-kvm-0.14.1/bin/qemu-system-x86_64
guestfs_get_recovery_proc: 1
guestfs_get_selinux: 0
guestfs_get_trace: 0
guestfs_get_verbose: 1
host_cpu: x86_64
Launching appliance, timeout set to 120 seconds.
libguestfs: [00000ms] febootstrap-supermin-helper --verbose -f checksum '/usr/local/home/dek/sw/libguestfs-1.12.3/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/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d
checking modpath /lib/modules/2.6.32-gg508-generic.disabled is a directory
picked vmlinuz-2.6.32-gg508-generic.disabled because modpath /lib/modules/2.6.32-gg508-generic.disabled exists
checking modpath /lib/modules/2.6.38.8-experimental4 is a directory
picked vmlinuz-2.6.38.8-experimental4 because modpath /lib/modules/2.6.38.8-experimental4 exists
supermin helper [00000ms] finished creating kernel
supermin helper [00000ms] visiting /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d
supermin helper [00000ms] visiting /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d/base.img
supermin helper [00000ms] visiting /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d/daemon.img
supermin helper [00000ms] visiting /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d/hostfiles
supermin helper [00016ms] visiting /usr/local/home/dek/sw/libguestfs-1.12.3/lib/guestfs/supermin.d/init.img
supermin helper [00049ms] finished creating appliance
libguestfs: [00053ms] begin testing qemu features
libguestfs: [00065ms] finished testing qemu features
libguestfs: accept_from_daemon: 0x22df410 g->state = 1
libguestfs: [00066ms] /home/dek/sw/qemu-kvm-0.14.1/bin/qemu-system-x86_64 \
    -drive file=/tmp/libguestfs-test-tool-sda-iWMYOJ,cache=off,format=raw,if=virtio \
    -nodefconfig \
    -enable-kvm \
    -nodefaults \
    -nographic \
    -m 500 \
    -no-reboot \
    -no-hpet \
    -device virtio-serial \
    -serial stdio \
    -chardev socket,path=/tmp/libguestfsMqHmAh/guestfsd.sock,id=channel0 \
    -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
    -kernel /var/tmp/.guestfs-88619/kernel.23376 \
    -initrd /var/tmp/.guestfs-88619/initrd.23376 \
    -append 'panic=1 console=ttyS0 udevtimeout=300 noapic acpi=off printk.time=1 cgroup_disable=memory selinux=0 guestfs_verbose=1 TERM=rxvt ' \
    -drive file=/var/tmp/.guestfs-88619/root.23376,snapshot=on,if=virtio,cache=unsafe
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Linux version 2.6.38.8-experimental4 (root@redacted.com) (gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) ) #2 SMP Mon Jun 27 14:14:51 PDT 2011
[    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=rxvt 
[    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: 00000000feffc000 - 00000000ff000000 (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] PAT not supported by CPU.
[    0.000000] found SMP MP-table at [ffff8800000fdbf0] fdbf0
[    0.000000] init_memory_mapping: 0000000000000000-000000001f3fd000
[    0.000000] RAMDISK: 1f2fc000 - 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] kvm-clock: Using msrs 12 and 11
[    0.000000] kvm-clock: cpu 0, msr 0:1a93a41, boot clock
[    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:dfbfc000)
[    0.000000] Booting paravirtualized kernel on KVM
[    0.000000] setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:1 nr_node_ids:1
[    0.000000] PERCPU: Embedded 28 pages/cpu @ffff88001f000000 s83648 r8192 d22848 u2097152
[    0.000000] kvm-clock: cpu 0, msr 0:1f013a41, primary cpu clock
[    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=rxvt 
[    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: 489508k/511988k available (5440k kernel code, 468k absent, 22012k reserved, 5307k data, 840k 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-based detection of stalled CPUs is disabled.
[    0.000000] NR_IRQS:4352 nr_irqs:256 16
[    0.000000] Console: colour dummy device 80x25
[    0.000000] console [ttyS0] enabled
[    0.000000] Detected 2666.760 MHz processor.
[    0.000000] TSC resynchronization disabled on non-AMD processors
[    0.020000] Calibrating delay loop (skipped) preset value.. 5333.52 BogoMIPS (lpj=26667600)
[    0.020000] pid_max: default: 32768 minimum: 301
[    0.020000] Security Framework initialized
[    0.020000] AppArmor: AppArmor initialized
[    0.020000] Dentry cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.020000] Inode-cache hash table entries: 32768 (order: 6, 262144 bytes)
[    0.020000] Mount-cache hash table entries: 256
[    0.020000] Initializing cgroup subsys ns
[    0.020000] ns_cgroup deprecated: consider using the 'clone_children' flag without the ns_cgroup.
[    0.020000] Initializing cgroup subsys cpuacct
[    0.020000] Initializing cgroup subsys memory
[    0.020000] Initializing cgroup subsys devices
[    0.020000] Initializing cgroup subsys freezer
[    0.020000] Initializing cgroup subsys net_cls
[    0.020000] mce: CPU supports 10 MCE banks
[    0.020000] SMP alternatives: switching to UP code
[    0.031479] Freeing SMP alternatives: 24k freed
[    0.031811] ftrace: allocating 20794 entries in 82 pages
[    0.040051] Setting APIC routing to flat
[    0.040385] CPU0: Intel QEMU Virtual CPU version 0.14.1 stepping 03
[    0.160050] Performance Events: unsupported p6 CPU model 2 no PMU driver, software events only.
[    0.160898] Brought up 1 CPUs
[    0.161167] Total of 1 processors activated (5333.52 BogoMIPS).
[    0.161686] devtmpfs: initialized
[    0.162127] print_constraints: dummy: 
[    0.162469] NET: Registered protocol family 16
[    0.163074] PCI: Using configuration type 1 for base access
[    0.164322] bio: create slab <bio-0> at 0
[    0.164848] ACPI: Interpreter disabled.
[    0.165193] vgaarb: loaded
[    0.165576] SCSI subsystem initialized
[    0.166057] usbcore: registered new interface driver usbfs
[    0.166485] usbcore: registered new interface driver hub
[    0.166864] usbcore: registered new device driver usb
[    0.167280] PCI: Probing PCI hardware
[    0.168467] pci 0000:00:01.3: quirk: [io  0xb000-0xb03f] claimed by PIIX4 ACPI
[    0.168965] pci 0000:00:01.3: quirk: [io  0xb100-0xb10f] claimed by PIIX4 SMB
[    0.170864] pci 0000:00:01.0: PIIX/ICH IRQ router [8086:7000]
[    0.171473] NetLabel: Initializing
[    0.171709] NetLabel:  domain hash size = 128
[    0.172013] NetLabel:  protocols = UNLABELED CIPSOv4
[    0.172365] NetLabel:  unlabeled traffic allowed by default
[    0.172774] Switching to clocksource kvm-clock
[    0.174699] AppArmor: AppArmor Filesystem Enabled
[    0.175040] pnp: PnP ACPI: disabled
[    0.176383] NET: Registered protocol family 2
[    0.176729] IP route cache hash table entries: 4096 (order: 3, 32768 bytes)
[    0.177329] TCP established hash table entries: 16384 (order: 6, 262144 bytes)
[    0.177878] TCP bind hash table entries: 16384 (order: 6, 262144 bytes)
[    0.178349] TCP: Hash tables configured (established 16384 bind 16384)
[    0.178807] TCP reno registered
[    0.179024] UDP hash table entries: 256 (order: 1, 8192 bytes)
[    0.179418] UDP-Lite hash table entries: 256 (order: 1, 8192 bytes)
[    0.179887] NET: Registered protocol family 1
[    0.179887] Switched to NOHz mode on CPU #0
[    0.179887] pci 0000:00:00.0: Limiting direct PCI/PCI transfers
[    0.179887] pci 0000:00:01.0: PIIX3: Enabling Passive Release
[    0.179887] pci 0000:00:01.0: Activating ISA DMA hang workarounds
[    0.179887] Trying to unpack rootfs image as initramfs...
[    0.180065] Freeing initrd memory: 976k freed
[    0.180573] platform rtc_cmos: registered platform RTC device (no PNP device found)
[    0.181267] audit: initializing netlink socket (disabled)
[    0.181672] type=2000 audit(1313186460.170:1): initialized
[    0.192617] HugeTLB registered 2 MB page size, pre-allocated 0 pages
[    0.194333] VFS: Disk quotas dquot_6.5.2
[    0.194657] Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    0.195424] fuse init (API version 7.16)
[    0.195797] msgmni has been set to 958
[    0.196211] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 253)
[    0.196722] io scheduler noop registered
[    0.197009] io scheduler deadline registered (default)
[    0.197406] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[    0.197820] pciehp: PCI Express Hot Plug Controller Driver version: 0.4
[    0.198454] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    0.219964] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[    0.220670] Linux agpgart interface v0.103
[    0.221807] brd: module loaded
[    0.222457] loop: module loaded
[    0.223121] scsi0 : ata_piix
[    0.223395] scsi1 : ata_piix
[    0.223622] ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc000 irq 14
[    0.224054] ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc008 irq 15
[    0.224753] Fixed MDIO Bus: probed
[    0.225021] PPP generic driver version 2.4.2
[    0.225354] tun: Universal TUN/TAP device driver, 1.6
[    0.225682] tun: (C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>
[    0.226144] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    0.226601] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    0.227009] uhci_hcd: USB Universal Host Controller Interface driver
[    0.227482] i8042: PNP: No PS/2 controller found. Probing ports directly.
[    0.228324] serio: i8042 KBD port at 0x60,0x64 irq 1
[    0.228658] serio: i8042 AUX port at 0x60,0x64 irq 12
[    0.229349] mousedev: PS/2 mouse device common for all mice
[    0.229918] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input0
[    0.230707] rtc_cmos rtc_cmos: rtc core: registered rtc_cmos as rtc0
[    0.231159] rtc0: alarms up to one day, 114 bytes nvram
[    0.231590] device-mapper: ioctl: 4.19.1-ioctl (2011-01-07) initialised: dm-devel@redhat.com
[    0.232208] device-mapper: multipath: version 1.2.0 loaded
[    0.232579] device-mapper: multipath round-robin: version 1.0.0 loaded
[    0.233113] cpuidle: using governor ladder
[    0.233384] cpuidle: using governor menu
[    0.233784] TCP cubic registered
[    0.234107] NET: Registered protocol family 10
[    0.234712] NET: Registered protocol family 17
[    0.235019] Registering the dns_resolver key type
[    0.235458] registered taskstats version 1
[    0.235914] rtc_cmos rtc_cmos: setting system clock to 2011-08-12 22:00:59 UTC (1313186459)
[    0.236474] BIOS EDD facility v0.16 2004-Jun-25, 0 devices found
[    0.236860] EDD information not available.
[    0.384308] Freeing unused kernel memory: 840k freed
[    0.385874] Write protecting the kernel read-only data: 10240k
[    0.393138] Freeing unused kernel memory: 684k freed
[    0.402678] Freeing unused kernel memory: 1776k freed
febootstrap: mounting /proc
febootstrap: uptime: 0.40 0.19
febootstrap: ext2 mini initrd starting up
febootstrap: mounting /sys
febootstrap: internal insmod libcrc32c.ko
insmod: init_module: libcrc32c.ko: Unknown symbol in module
febootstrap: internal insmod crc32c-intel.ko
insmod: init_module: crc32c-intel.ko: No such device
febootstrap: internal insmod crc-itu-t.ko
febootstrap: internal insmod crc32c.ko
febootstrap: internal insmod crc-ccitt.ko
febootstrap: internal insmod crc7.ko
febootstrap: internal insmod scsi_transport_spi.ko
febootstrap: internal insmod sym53c8xx.ko
febootstrap: internal insmod sparse-keymap.ko
febootstrap: internal insmod ideapad-laptop.ko
insmod: init_module: ideapad-laptop.ko: No such device
febootstrap: internal insmod virtio_ring.ko
febootstrap: internal insmod virtio.ko
febootstrap: internal insmod virtio-rng.ko
febootstrap: internal insmod virtio_console.ko
febootstrap: internal insmod virtio_balloon.ko
febootstrap: no ext2 root device found
Please include FULL verbose output in your bug report.
[    0.423999] Kernel panic - not syncing: Attempted to kill init!
[    0.424572] Pid: 1, comm: init Not tainted 2.6.38.8-experimental4 #2
[    0.425087] Call Trace:
[    0.425298]  [<ffffffff81542e4d>] ? panic+0x91/0x1b0
[    0.425757]  [<ffffffff810eaaa0>] ? perf_event_exit_task+0xc0/0x210
[    0.426266]  [<ffffffff8105f2c8>] ? do_exit+0x728/0x860
[    0.426669]  [<ffffffff8105f451>] ? do_group_exit+0x51/0xc0
[    0.427089]  [<ffffffff8105f4d7>] ? sys_exit_group+0x17/0x20
[    0.427515]  [<ffffffff8100bf82>] ? system_call_fastpath+0x16/0x1b
[    0.428127] Rebooting in 1 seconds..libguestfs: error: unexpected end of file when reading from daemon.
See earlier debug messages.
Or you can run 'libguestfs-test-tool' and post the complete output into
a bug report or message to the libguestfs mailing list.
libguestfs: child_cleanup: 0x22df410: child process died
libguestfs-test-tool: failed to launch appliance
libguestfs: closing guestfs handle 0x22df410 (state 0)


On Fri, Aug 12, 2011 at 2:35 PM, David Konerding <dek@konerding.com> wrote:


On Fri, Aug 12, 2011 at 2:12 PM, Richard W.M. Jones <rjones@redhat.com> wrote:
On Fri, Aug 12, 2011 at 02:00:20PM -0700, David Konerding wrote:
> By download and unpack, do you mean a kernel source package, or a kernel
> package from a later Ubuntu release such as 10.10?

You could compile it from source, but it'd be easier to just take a
compiled binary from any later Ubuntu (11.04 seems like the best bet
since it's the one we use).  Don't forget you need the modules
directory as well as vmlinuz.


Looks like this is moot.  Turns out my kernel team has a test kernel (2.6.38, I feel like I'm in the 23rd century) and I'm getting my workstation converted to that.
 
Rich.

--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/