Erasure Code Calculator
Erasure coding is a mechanism to protect pieces of information against data loss. To achieve that, information, such as files, is broken up into a number of data chunks (k) and algorithmically combined into parity chunks (m). The total amount of chunks (n) is then spread around multiple storage devices and / or cluster nodes. This calculator helps to determine the raw and usable capacity of a storage solution using erasure codes.
Number of servers
Number of drives per server
Capacity per drive
TiB
Erasure Coding Data Chunks (k)
Erasure Coding Parity Chunks (m)
Erasure Coding Total Chunks (n)
Usable capacity
128 TiB
Raw storage capacity
192 TiB
Available raw storage capacity
67%
Erasure coding overhead
50%
Erasure coding usage
64 TiB
Comparison to replication
Usable capacity with 2 replicas
96 TiB (-33%)
Usable capacity with 3 replicas
64 TiB (-66%)