Before upgrading the Ceph cluster, you need to have both the underlying SUSE Linux Enterprise Server and SUSE Enterprise Storage correctly registered against SCC or SMT. You can upgrade daemons in your cluster while the cluster is online and in service. Certain types of daemons depend upon others. For example Ceph RADOS Gateways depend upon Ceph monitors and Ceph OSD daemons. We recommend upgrading in this order:
Admin node (if you deployed the cluster using the admin node).
Ceph OSD daemons.
Ceph RADOS Gateways.
iSCSI gateways (refer to https://www.suse.com/documentation/ses-3/book_storage_admin/data/ceph_upgrade_2_1to3.html#ceph_upgrade_2_1to3_iscsi_up for more details).
HINT: We recommend upgrading all the daemons of a specific type—for example all monitor daemons or all OSD daemons—one by one to ensure that they are all on the same release. We also recommend that you upgrade all the daemons in your cluster before you try to exercise new functionality in a release.
After all the daemons of a specific type are upgraded, check their status.
Ensure each monitor has rejoined the quorum after all monitors are upgraded:
ceph mon stat
Ensure each Ceph OSD daemon has rejoined the cluster after all OSDs are upgraded:
ceph osd stat