3 node erasure coding cluster

[djakupovic]

your documentation states that you need at least 4 nodes with an example of 12+4. why is 3 node not possible with 4+2 e.g?

This would be the setting in minio, 6 drives, 3 nodes:
MINIO_STORAGE_CLASS_STANDARD: "EC:2" # use only 2 parity disks
MINIO_STORAGE_CLASS_RRS: "EC:1" # set x-amz-storage-class: REDUCED_REDUNDANCY header for an upload to only use 1 parity

It would be great if a 3 node cluster is possible in future, or maybe it is even now. If it is, what to do?

Best

[loverustfs]

Hi @djakupovic ,

RustFS and MinIO do not recommend three nodes. Three nodes cannot achieve the optimal load.

The reasons are:

1. Ceph designs using three replicas generally use three replicas or two replicas;

2. MinIO and RustFS only have erasure codes in their designs;

It is not that three nodes are not good. It is that the data risk will increase when three nodes are deployed. You can deploy three nodes using MinIO and RustFS.

However, this is not the configuration recommended by best practices.

[djakupovic]

Ok thank you for the reply, can you please update your documentation stating this, because for me I understood as if it a hard requirement to have 4 nodes

[loverustfs]

@djakupovic ,

No, three nodes can also run, but the data risk of three nodes will be much higher.

[djakupovic]

Yes I know, I thought rustfs works differently than minio. thanks a lot

[loverustfs]

Yes I know, I thought rustfs works differently than minio. thanks a lot

Ok, thanks.
What's the difference?