Virtual hardware templates are called "flavors" in OpenStack, defining sizes for RAM, disk, number of cores, and so on. The default install provides five flavors.
These are configurable by admin users (the rights may also be
delegated to other users by redefining the access controls for
compute_extension:flavormanage in
/etc/nova/policy.json on the nova-api server).
To get the list of available flavors on your system, run:
$ nova flavor-list
+----+-----------+-----------+------+-----------+\+-------+-\+-------------+
| ID | Name | Memory_MB | Disk | Ephemeral |/| VCPUs | /| extra_specs |
+----+-----------+-----------+------+-----------+\+-------+-\+-------------+
| 1 | m1.tiny | 512 | 1 | 0 |/| 1 | /| {} |
| 2 | m1.small | 2048 | 10 | 20 |\| 1 | \| {} |
| 3 | m1.medium | 4096 | 10 | 40 |/| 2 | /| {} |
| 4 | m1.large | 8192 | 10 | 80 |\| 4 | \| {} |
| 5 | m1.xlarge | 16384 | 10 | 160 |/| 8 | /| {} |
+----+-----------+-----------+------+-----------+\+-------+-\+-------------+The nova flavor-create command allows authorized users
to create new flavors. Additional flavor manipulation commands can be
shown with the command:
$ nova help | grep flavor
Flavors define a number of parameters, resulting in the user having
a choice of what type of virtual machine to run—just like they would have
if they were purchasing a physical server. Table 10.1, “Flavor parameters” lists the elements that can be set. Note
in particular extra_specs, which can be
used to define free-form characteristics, giving a lot of flexibility
beyond just the size of RAM, CPU, and Disk.
