Switch Flavors
Flavors are pre-configured templates that specify the amount of CPU, RAM, and disk space available to a VM. Switching flavors refers to changing the flavor of an existing VM, essentially upgrading or downgrading its resources according to the new flavor's specifications.
Before You Begin
We strongly recommend taking a snapshot of your volume before performing any flavor switch operation. This ensures you can fully restore the VM to its previous state in case of unexpected failures during the resize process.
Benefits of Switching Flavors
Scalability: Switching flavors allows users to scale their VMs up or down based on changing resource requirements. For example, if an application running on a VM experiences higher demand, you can switch to a flavor with more CPU and RAM to handle the increased load.
Cost Efficiency: By switching to a smaller flavor when fewer resources are needed, users can reduce their cloud costs.
Flexibility: As business needs evolve, the ability to quickly adjust the resources of a VM without having to create a new instance provides flexibility and minimizes downtime.
Performance Optimization: Switching to a more powerful flavor can improve the performance of applications running on a VM, ensuring they have sufficient resources to operate efficiently.
Important
Resizing an instance will trigger a reboot. If you revert the resize, the instance will be rebooted again.
How to Switch Flavors
- Resize the instance: navigate to Project > Compute > Instances and in the Actions dropdown select
Resize Instance. In the popup window that appears choose the new flavor and click Resize. - Verification: Ensure the instance is functioning correctly with the new resources.
- Revert Resize/Migrate: If there are any issues in the resized instance, you can rollback to the previous state
by selecting
Revert Resize/Migratein the Actions dropdown. - Confirm Resize: After resizing, you will need to confirm the operation to finalize the changes.
The instance will enter a
Confirm or Revert Resize/Migratestate until confirmation. Confirmation timeout is set to 1h. After that period the resize will be automatically confirmed.
Suppose you have an instance with 2 vCPUs and 2GB of RAM and need to scale up to 4 vCPUs and 8GB of RAM:
- Original Flavor: c002r002 (2 vCPUs, 2GB RAM)
- New Flavor: c004r008 (4 vCPUs, 8GB RAM)
Check current size of an instance:
Example output
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | AUTO |
...
| flavor | description=, disk='0', ephemeral='0', , id='c002r002', is_disabled=, is_public='True', location=, name='c002r002', original_name='c002r002', ram='2048', rxtx_factor=, swap='0', vcpus='2' |
...
| volumes_attached | delete_on_termination='False', id='c76abb8a-2712-4dea-a31c-8c9702e0b20b' |
| | delete_on_termination='False', id='73d06e23-6de8-40b0-b72c-205924bf6f6c' |
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
List available flavors to find the desired new flavor ID:
Example output
+--------+----------+--------+------+-----------+-------+-----------+
| ID | Name | RAM | Disk | Ephemeral | VCPUs | Is Public |
+--------+----------+--------+------+-----------+-------+-----------+
| 001001 | c001r001 | 1024 | 0 | 0 | 1 | True |
...
| 004008 | c004r008 | 8192 | 0 | 0 | 4 | True |
...
| 032256 | c032r256 | 262144 | 0 | 0 | 32 | True |
+--------+----------+--------+------+-----------+-------+-----------+
Resize the instance (no output; check status separately):
Check server status (if the status is RESIZE, then the resize operation is still ongoing).
After the resize operation completes, the instance will enter VERIFY_RESIZE status, meaning that the resize
operation is done but needs to be confirmed.
Example output
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
...
| status | VERIFY_RESIZE |
...
| volumes_attached | delete_on_termination='False', id='c76abb8a-2712-4dea-a31c-8c9702e0b20b' |
| | delete_on_termination='False', id='73d06e23-6de8-40b0-b72c-205924bf6f6c' |
+-------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Revert the resize if there are any issues with the resized instance (no immediate output; the instance status will
change to REVERT_RESIZE during the revert process).
After the revert is complete, the instance will return to ACTIVE with its original flavor.
Confirm the resize if the instance is functioning as expected (no immediate output):
Check the instance status:
To confirm the number of CPUs log in to the instance and run:
Example output
To confirm the amount of RAM run: