Can the provisioned storage size of an RDS decrease if auto scaling is enabled?


I made the RDS with t4g.small instance and 100GiB of general purpose SSD(gp2)

single AZ, no Proxy but enabled storage auto scaling

After testing for 133 hours, I reviewed the billed charges, but there was a part that I couldn't understand.


why does the charge for storage usage is recorded for 17.655GB-Mo, I thought it should have been 100GB-Mo that I provisioned at the very first

of course it's thanks for me that they didn't charge the whole provisioned storage

but it makes me confused.

1 Answer
Accepted Answer


Memory is billed based GB-Mo: so 133h is approx 133 / (24h x 31d) = 17.8% of a month . So, 17.665GB-Mon is not that far 17.8&% of 100 GB if you take into account some rounding errorrs, etc.

Hence your current bill. It will increase if you let it run for longer based on the ratio above.



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