When then content of the authorized_keys and/or known_hosts files is too big and live migration is enabled, the cloud-compute-relation-failed portion of the charm fails with the following trace :
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/var/lib/juju/agents/unit-nova-cloud-controller-1/charm/hooks/cloud-compute-relation-changed", line 293, in compute_changed
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK authorized_keys=ssh_authorized_keys_b64())
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/var/lib/juju/agents/unit-nova-cloud-controller-1/charm/hooks/charmhelpers/core/hookenv.py", line 201, in relation_set
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK subprocess.check_call(relation_cmd_line)
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/usr/lib/python2.7/subprocess.py", line 506, in check_call
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK retcode = call(*popenargs, **kwargs)
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/usr/lib/python2.7/subprocess.py", line 493, in call
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK return Popen(*popenargs, **kwargs).wait()
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK errread, errwrite)
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK raise child_exception
P121C-2-1-15557:2014-03-27 03:17:57 INFO juju.worker.uniter context.go:255 HOOK OSError: [Errno 7] Argument list too long
P121C-2-1-15557:2014-03-27 03:17:57 ERROR juju.worker.uniter uniter.go:350 hook failed: exit status 1
