The previous section showed how you can add an HAIZEA parameter to your OpenNebula VM template to request a simple advance reservation. The three Haizea options (start, duration, and preemptible) can take other values:
Usually, you will want to use these options to create one of Haizea's supported lease types:
When you need your VM available at a specific time, this is called an advance reservation, or AR. The VM we used above is an example of an AR:
HAIZEA = [ start = "+00:00:30", duration = "00:01:00", preemptible = "no" ]
Of course, instead of specifying that you want your VM to start after a certain amount of time has passed (30 seconds, in this case), you can also specify an exact start time:
HAIZEA = [ start = "2008-11-04 11:00:00", duration = "03:00:00", preemptible = "no" ]
NOTE: Haizea currently only supports non-preemptible ARs.
When you instruct Haizea to determine the start time on a best-effort basis, your request will be allocated resources as soon as they become available. Take into account that your request may be placed on a queue, and you'll have to wait until your turn is up. You can use the haizea-list-leases and haizea-show-queue to check on the state of your lease.
HAIZEA = [ start = "best_effort", duration = "01:00:00", preemptible = "yes" ]
A best-effort VM can be preemptible or non-preemptible. If you request a non-preemptible VM, you may still have to wait in the queue until you get your resources but, once you do, no one can take them from you.
Sometimes, you need a VM right now or not at all. In that case, you can set the starting time to now.
HAIZEA = [ start = "now", duration = "unlimited", preemptible = "no" ]
Borja Sotomayor 2009-12-17