virt-install will fail with cryptic message if not enough memory available for VM.

[PaulSchulz]

Then trying to use 'virt-install' to install a domain which had been created with 'virt-convirt'
the install failed.

The cryptic message was:
$ virt-image --connect=qemu+ssh:///system dir/image.xml

Creating guest <ImageName>...
ERROR Unable to read from monitor: Connection reset by peer
Domain installation does not appear to have been successful.
If it was, you can restart your domain by running:
  virsh --connect qemu+ssh:///system start <ImageName>
otherwise, please restart your installation.

The problem was that I was trying to install a domain with 8G, when the system only had 4G of physical memory.

Reducing the amount of memory defined in the XML file to 2G, and the running the command again fixed the issue.

Messages in the log file pointed to an erroneous apparmor bug - https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/545302

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: virtinst 0.600.1-1ubuntu3.2
ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24
Uname: Linux 3.2.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Fri Sep 7 17:02:23 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=xterm
 PATH=(custom, user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: virtinst
UpgradeStatus: No upgrade log present (probably fresh install)