I've got a couple of virtualization servers running Ubuntu 12.04 and Virtualbox and just bought a Synology NAS which I plan to use as an iSCSI target to serve storage for the VMs. I realize that enterprise installations with backup generators and staff have to worry about this, but I want my whole setup to come up automatically in sequence if everything was powered off and I just went down the rack hitting power buttons. So before my init scripts launch the VMs they'd have to wait for the Synology box with its iSCSI targets to become available.
Before I reinvent the wheel, does anyone have an Upstart script that waits (with a timeout) for an iSCSI target to become available?