This tool can help to choose the required amount of replicas in a Swift cluster, based on the wanted object durability. If you need a lower risk to loose an object, you can increase the number of replicas for objects in your cluster. You can even use different number of replicas for different classes of data using Swift Storage Policies.
With the choosen parameters (see below), the calculated probability to loose one object of 5GB size in a year is: .
Object size in bytes | |
Rebuild time in hours | |
Annual Failure Rate. Probability for a disk failure in one year | |
Rebuild Failure Rate. Probability for a disk failure during rebuild | |
Probability for an unrecoverable error per bit read |