creation of /dev/disk/by-{id,path}, so if we fail to open the directory, retry
up to 5 seconds.  This is only likely to happen on hosts that are:

1) diskless (so /dev/disk/by-{id,path} doesn't exist already), and
2) slow, and/or heavily loaded (meaning that udev can take some time to create
the /dev nodes).
Signed-off-by: NChris Lalancette <clalance@redhat.com>