Pay-as-you-go is a billing method that allows you to use resources before you pay for them. You can purchase and release resources based on your business requirements. You do not need to purchase a large number of resources in advance. This topic describes the billing rules of Apsara File Storage NAS (NAS), the use scenarios of the pay-as-you-go billing method, how you are billed if you change the specifications of a pay-as-you-go NAS file system, and the impact of overdue payments.
Pricing
For more information about the prices of NAS file systems, see Apsara File Storage NAS Pricing.
Billing rules
General-purpose NAS file systems: You are charged based on the actual resource usage. Bills are generated and fees are deducted from the balance of your Alibaba Cloud account at the end of each billing cycle. For more information, see Billing of General-purpose NAS file systems.
Extreme NAS file systems: You are charged based on the configured capacity. Bills are generated and fees are deducted from the balance of your Alibaba Cloud account at the end of each billing cycle. For more information, see Billing of Extreme NAS file systems.
Scenarios
The pay-as-you-go billing method is ideal for the following business scenarios:
Business with fluctuating resource usage
Business that requires temporary use of resources
Billable items
The following billable items of NAS support the pay-as-you-go billing method:
Storage usage of General-purpose NAS file systems (Capacity NAS file systems, Performance NAS file systems, and Premium NAS file systems)
Storage usage of the IA storage class
Read traffic of the IA storage class
Write traffic of the IA storage class
Purchased capacity of Extreme NAS file systems
Billing cycle
Fees are calculated on an hourly basis (UTC+8). After fees are calculated, a new billing cycle begins.
If the sum of the balance and vouchers in your Alibaba Cloud account is less than the amount that you need to pay, the system sends you a notification by text message or email.
Billing after specifications are changed
If you change the specifications of a pay-as-you-go NAS file system, a new order is generated and you are charged based on the new specifications. The original order becomes invalid.
If you change the specifications within one hour, multiple bills are generated. The start and end time of each bill correspond to the time when the specifications are changed. For example, you create a pay-as-you-go Extreme NAS file system at 11:00:00 with a capacity of 1 TiB and scale it up to 2 TiB at 11:30:00. Two bills are generated during the period from 11:00 to 12:00.
The duration of the first bill is from 11:00:00 to 11:30:00 and you are charged based on the price of the 1 TiB capacity.
The duration of the second bill is from 11:30:00 to 12:00:00 and you are charged based on the price of the 2 TiB capacity.
After you create a pay-as-you-go Extreme NAS file system, you can change the storage capacity of the file system. For more information, see Scale up an Extreme NAS file system.
Overdue payments
If you have overdue payments within your Alibaba Cloud account, you are unable to use pay-as-you-go resources. In this case, you are unable to use NAS file systems and your data may be cleared. To prevent negative impacts on your business, we recommend that you add funds to your Alibaba Cloud account at the earliest opportunity. For information about status changes of NAS resources when overdue payments occur, see Overdue payments.