Server size is changed by applying a different flavor to the server. Before you begin, use nova flavor-list to review the flavors available to you.
$ nova flavor-list
+----+-----------+-----------+------+-----------+------+-------+-------------+
| ID | Name | Memory_MB | Disk | Ephemeral | Swap | VCPUs | RXTX_Factor |
+----+-----------+-----------+------+-----------+------+-------+-------------+
| 1 | m1.tiny | 512 | 0 | 0 | | 1 | 1.0 |
| 2 | m1.small | 2048 | 10 | 20 | | 1 | 1.0 |
| 3 | m1.medium | 4096 | 10 | 40 | | 2 | 1.0 |
| 4 | m1.large | 8192 | 10 | 80 | | 4 | 1.0 |
| 5 | m1.xlarge | 16384 | 10 | 160 | | 8 | 1.0 |
+----+-----------+-----------+------+-----------+------+-------+-------------+
In this example, we'll take a server originally configured with the m1.tiny flavor and resize it to m1.small.
$ nova show acdfb2c4-38e6-49a9-ae1c-50182fc47e35
+------------------------+----------------------------------------------------------+
| Property | Value |
+------------------------+----------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-STS:power_state | 1 |
| OS-EXT-STS:task_state | None |
| OS-EXT-STS:vm_state | active |
| accessIPv4 | |
| accessIPv6 | |
| config_drive | |
| created | 2012-05-09T15:47:48Z |
| flavor | m1.tiny |
| hostId | de0c201e62be88c61aeb52f51d91e147acf6cf2012bb57892e528487 |
| id | acdfb2c4-38e6-49a9-ae1c-50182fc47e35 |
| image | maverick-image |
| key_name | |
| metadata | {} |
| name | resize-demo |
| private network | 172.16.101.6 |
| progress | 0 |
| public network | 10.4.113.6 |
| status | ACTIVE |
| tenant_id | e830c2fbb7aa4586adf16d61c9b7e482 |
| updated | 2012-05-09T15:47:59Z |
| user_id | de3f4e99637743c7b6d27faca4b800a9 |
+------------------------+----------------------------------------------------------+
Use the resize command with the server's ID (6beefcf7-9de6-48b3-9ba9-e11b343189b3) and the ID of the desired flavor (2):
$ nova resize 6beefcf7-9de6-48b3-9ba9-e11b343189b3 2
While the server is rebuilding, its status will be displayed as RESIZING.
$ nova list
+--------------------------------------+-------------+--------+-----------------------------------------+
| ID | Name | Status | Networks |
+--------------------------------------+-------------+--------+-----------------------------------------+
| 970e4ca0-f9b7-4c44-80ed-bf0152c96ae1 | resize-demo | RESIZE | private=172.16.101.6, public=10.4.113.6 |
+--------------------------------------+-------------+--------+-----------------------------------------+
When the resize operation is completed, the status displayed is VERIFY_RESIZE. This prompts the user to verify that the operation has been successful; to confirm:
$ nova resize-confirm 6beefcf7-9de6-48b3-9ba9-e11b343189b3
However, if the operation has not worked as expected, you can revert it by doing:
$ nova resize-revert 6beefcf7-9de6-48b3-9ba9-e11b343189b3
In both cases, the server status should go back to ACTIVE.
