6 Additional OpenNebula configuration options

When running Haizea with OpenNebula, you must specify at least the host option in the [opennebula] section of the configuration file. However, there are additional options in other sections that you can tweak:

1 Wakeup interval

This is the interval, in seconds, at which Haizea will wake up to process pending requests in OpenNebula. The default is 60 seconds.

[scheduling]
...
wakeup-interval: 60
...

2 Suspend/resume rate interval

This option provides Haizea with an estimate of how long it takes for OpenNebula to suspend or resume a virtual machine. This is estimated in MB per second, and is largely dependent on the disk read/write transfer speeds on your system (so, if a VM has 1024 MB of memory, and the suspend rate is estimated to be 64MB/s, Haizea will estimate that suspension will take 16 seconds). If you do not specify a value, Haizea will conservatively assume a rate of 32MB/s. A good estimate will allow Haizea to more correctly schedule resources, but an incorrect estimate will not result in an error (although a warning will be noted in the logs).

[scheduling]
...
suspend-rate: 32
resume-rate: 32
...

Additionally, since OpenNebula currently only supports suspending to a global filesystem (i.e., the RAM file created when suspending a VM is saved to a global filesystem, such as an NFS drive), you will need to specify that suspensions and resumptions must be globally exclusive (to make sure that no more than one RAM file is being saved to the global filesystem at any one time). You can control this using the suspendresume-exclusion option in the [scheduling] section:

[scheduling]
...
suspendresume-exclusion: global
...

This option is set to global in the sample OpenNebula configuration file, but defaults to local when not specified.

3 Non-schedulable interval

The minimum amount of time that must pass between when a request is scheduled to when it can actually start (i.e., this makes sure that the scheduling function doesn't make reservations with starting times that will be in the past by the time the scheduling function ends). The default (10 seconds) should be good for most configurations, but may need to be increased if you're dealing with exceptionally high loads.

[scheduling]
...
non-schedulable-interval: 10
...