That is why i am asking that question about upgrade instruction.
I really don`t understand, how to upgrade/reinstall CentOS 7 to 8 without affecting the
work of cluster.
As i know, this process is easier on Debian, but we deployed our cluster Nautilus on
CentOS because there weren`t any packages for 14.x for Debian Stretch (9) or Buster(10).
P.s.: if this is even possible, i would like to know how to upgrade servers with CentOs7 +
ceph 14.2.8 to Debian 10 with ceph 15.2.0 (we have servers with OSD only and 3 servers
with Mon/Mgr/Mds)