diff --git a/docs/erasure/storage-class/README.md b/docs/erasure/storage-class/README.md index 8db97e42d..b4bac474e 100644 --- a/docs/erasure/storage-class/README.md +++ b/docs/erasure/storage-class/README.md @@ -2,6 +2,8 @@ MinIO server supports storage class in erasure coding mode. This allows configurable data and parity disks per object. +This page is intended as a summary of MinIO Erasure Coding. For a more complete explanation, see https://docs.min.io/minio/baremetal/concepts/erasure-coding.html. + ## Overview MinIO supports two storage classes, Reduced Redundancy class and Standard class. These classes can be defined using environment variables @@ -43,7 +45,16 @@ You can calculate _approximate_ storage usage ratio using the formula - total dr Parity blocks can not be higher than data blocks, so `STANDARD` storage class parity can not be higher than N/2. (N being total number of disks) -Default value for `STANDARD` storage class is `N/2` (N is the total number of drives). +The default value for the `STANDARD` storage class depends on the number of volumes in the erasure set: + +| Erasure Set Size | Default Parity (EC:N) | +|------------------|-----------------------| +| 5 or fewer | EC:2 | +| 6-7 | EC:3 | +| 8 or more | EC:4 | + +Prior to the ``RELEASE.2021-01-30T00-20-58Z`` MinIO release, the default `STANDARD` value was `EC(N/2)` where `N` was the number of erasure set drives. +For more complete documentation on Erasure Set sizing, see the [MinIO Documentation on Erasure Sets](https://docs.min.io/minio/baremetal/concepts/erasure-coding.html#erasure-sets). ### Allowed values for REDUCED_REDUNDANCY storage class