Comment 3 for bug 1236531

So, very unscientific. But 2 systems launched with eatmydata enabled on trusty on azure. 2 systems without. Systems here were 'extrasmall' (670M memory).
cloud-config to do this is:
| system_info:
| apt_get_wrapper:
| enabled: False

The /var/log/cloud-init.log will have something like:
Jan 9 15:18:27 sm-eatdata0 [CLOUDINIT] util.py[DEBUG]: apt-install [eatmydata apt-get --option=Dpkg::Options::=--force-confold --option=Dpkg::options::=--force-unsafe-io --assume-yes --quiet install bzr pastebinit ubuntu-dev-tools ccache bzr-builddeb vim-nox git-core lftp] took 105.916 seconds

Jan 9 15:26:20 sm-realsave0 [CLOUDINIT] util.py[DEBUG]: apt-install [apt-get --option=Dpkg::Options::=--force-confold --option=Dpkg::options::=--force-unsafe-io --assume-yes --quiet install bzr pastebinit ubuntu-dev-tools ccache bzr-builddeb vim-nox git-core lftp] took 88.697 seconds

eatmydata: 145.542 105.916
no-eatmydata: 88.697, 78.097

So... some interesting data there. I suspect that is a result of memory pressure on the vfs or something. Something to look at though.