System service offerings provide a choice of CPU speed, number of CPUs, tags, and RAM size, just as other service offerings do. But rather than being used for virtual machine instances and exposed to users, system service offerings are used to change the default properties of virtual routers, console proxies, and other system VMs. System service offerings are visible only to the CloudStack root administrator. CloudStack provides default system service offerings. The CloudStack root administrator can create additional custom system service offerings.
When CloudStack creates a virtual router for a guest network, it uses default settings which are defined in the system service offering associated with the network offering. You can upgrade the capabilities of the virtual router by applying a new network offering that contains a different system service offering. All virtual routers in that network will begin using the settings from the new service offering.
8.2.1. Creating a New System Service Offering
To create a system service offering:
Log in with admin privileges to the CloudStack UI.
In the left navigation bar, click Service Offerings.
In Select Offering, choose System Offering.
Click Add System Service Offering.
In the dialog, make the following choices:
Name. Any desired name for the system offering.
Description. A short description of the offering that can be displayed to users
System VM Type. Select the type of system virtual machine that this offering is intended to support.
Storage type. The type of disk that should be allocated. Local allocates from storage attached directly to the host where the system VM is running. Shared allocates from storage accessible via NFS.
# of CPU cores. The number of cores which should be allocated to a system VM with this offering
CPU (in MHz). The CPU speed of the cores that the system VM is allocated. For example, "2000" would provide for a 2 GHz clock.
Memory (in MB). The amount of memory in megabytes that the system VM should be allocated. For example, "2048" would provide for a 2 GB RAM allocation.
Network Rate. Allowed data transfer rate in MB per second.
Offer HA. If yes, the administrator can choose to have the system VM be monitored and as highly available as possible.
Storage Tags. The tags that should be associated with the primary storage used by the system VM.
Host Tags. (Optional) Any tags that you use to organize your hosts
CPU cap. Whether to limit the level of CPU usage even if spare capacity is available.
Public. Indicate whether the service offering should be available all domains or only some domains. Choose Yes to make it available to all domains. Choose No to limit the scope to a subdomain; CloudStack will then prompt for the subdomain's name.
