[ceph-users] Upgrad luminous -> mimic , any pointers?

I have a fairly dormant ceph luminous cluster on centos7 with stock kernel, and thought about upgrading it before putting it to more use. I can remember some page on the ceph website that had specific instructions mentioning upgrading from luminous. But I can't find it anymore, this page[0] even says I am viewing an unsupported version of ceph?? Any pointers aside from a default upgrade procedure? - I am using rbd, rgw and cephfs (only one mds) - Still using direct block devices (not lvm) - have one 1 pg active+clean+inconsistent since a year or so, that I am getting sentimentally attached to ;) [0] https://docs.ceph.com/docs/mimic/install/upgrading-ceph/#