Add new node to minio warm cluster

We now have a second minio cluster, currently just the node minio-fsn-02, that's used as a remote tier called warm by minio-01. However, that new cluster does not have enough storage space for the network-health bucket.

We want to:

• Document how a storage node can be added to a minio cluster
  • test the procedure in a local lab
• create a new VM in the fsn ganeti cluster (or on backup-storage-01?) and install minio
• add new VM as new node in the warm cluster (linked to minio-fsn-02)