You can only adjust the configurations of instances whose system disks and data disks are both cloud disks.
If your configuration adjustments do not take effect, please submit a ticket to contact us.
Yes. You can adjust the configurations of instances whose system disks and data disks are both cloud disks. For pay-as-you-go instances, you can upgrade or downgrade their configurations as many times as you want.
About 1 to 2 minutes.
You can view the cost details at the Billing Center after you upgrade the specifications or the configurations of the CVM instance.
After you upgrade a CVM instance, you must restart it to validate the new configurations. The upgrade operation will interrupt your business for a short period of time. We recommend that you upgrade instances when business is slow. After being upgraded, instances will seamlessly resume your business and will not require environment reconfiguration.
One possible reason is that you have purchased the instance at a discount but the downgraded configuration is calculated according to the original price of the instance. When the price of the instance purchased at a discount is lower than or equal to the original price of the instance, the estimated refund will be displayed as 0.
After you upgrade an instance, you must restart it on the Console or through an API.