uvt-kvm create fails, libvirt: Cannot write data: Broken pipe

What is the full Terminal output of the following command?

cat /etc/lsb-release; lsb_release -a; uname -a

Hi! Thank you for looking. There you go

DISTRIB_ID="elementary OS"
DISTRIB_RELEASE=0.3.2
DISTRIB_CODENAME=freya
DISTRIB_DESCRIPTION="elementary OS Freya"
No LSB modules are available.
Distributor ID: elementary OS
Description: elementary OS Freya
Release: 0.3.2
Codename: freya
Linux nb-myname 3.19.0-73-generic #81~14.04.1-Ubuntu SMP Wed Oct 19 00:03:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

An this is from the "working" laptop one:

DISTRIB_ID="elementary OS"
DISTRIB_RELEASE=0.3.2
DISTRIB_CODENAME=freya
DISTRIB_DESCRIPTION="elementary OS Freya"
No LSB modules are available.
Distributor ID: elementary OS
Description: elementary OS Freya
Release: 0.3.2
Codename: freya
Linux nb-dionysius 3.19.0-73-generic #81~14.04.1-Ubuntu SMP Wed Oct 19 00:03:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

I was wrong with "I can use virt-manager ... just fine". THIS vm I can't be started in any (even official) way - but others can.

$ sudo uvt-kvm create firsttest
uvt-kvm: error: libvirt: Cannot write data: Broken pipe

$ virsh list --all
 Id Name State
----------------------------------------------------
 3 ubuntu-server-2 running
 - devstackvm shut off
 - firsttest shut off

$ virsh start firsttest
error: Disconnected from qemu:///system due to I/O error
error: Failed to start domain firsttest
error: End of file while reading data: Input/output error

error: One or more references were leaked after disconnect from the hypervisor

$ virsh dumpxml firsttest
<domain type='kvm'>
  <name>firsttest</name>
  <uuid>163a9024-9c06-4bc4-909c-f287c3b47fed</uuid>
  <memory unit='KiB'>524288</memory>
  <currentMemory unit='KiB'>524288</currentMemory>
  <vcpu placement='static'>1</vcpu>
  <os>
    <type arch='x86_64' machine='pc-i440fx-xenial'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/bin/kvm-spice</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/uvtool/libvirt/images/firsttest.qcow'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='iso'/>
      <source file='/var/lib/uvtool/libvirt/images/firsttest-ds.qcow'/>
      <target dev='vdb' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </disk>
    <controller type='usb' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <interface type='network'>
      <mac address='52:54:00:e8:74:a9'/>
      <source network='default'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1'>
      <listen type='address' address='127.0.0.1'/>
    </graphics>
    <video>
      <model type='cirrus' vram='16384' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </memballoon>
  </devices>
</domain>

DISTRIB_ID="elementary OS"
DISTRIB_RELEASE=0.3.2
DISTRIB_CODENAME=freya
DISTRIB_DESCRIPTION="elementary OS Freya"

Elementary OS is not supported by the Ubuntu community. None of the "Ubuntu based" distributions are supported here.

I suggest you post on the Elementary OS forum:

https://elementaryforums.com/index.php