diff --git a/doc/rados/operations/stretch-mode.rst b/doc/rados/operations/stretch-mode.rst index 6baae7ce502ad..f797b5b91f4cb 100644 --- a/doc/rados/operations/stretch-mode.rst +++ b/doc/rados/operations/stretch-mode.rst @@ -211,45 +211,52 @@ deployments that have more than two data centers. Other commands ============== -If your tiebreaker monitor fails for some reason, you can replace it. Turn on -a new monitor and run: + +Replacing a failed tiebreaker monitor +------------------------------------- + +Turn on a new monitor and run the following command: .. prompt:: bash $ ceph mon set_new_tiebreaker mon. -This command will protest if the new monitor is in the same location as existing -non-tiebreaker monitors. This command WILL NOT remove the previous tiebreaker -monitor; you should do so yourself. +This command protests if the new monitor is in the same location as the +existing non-tiebreaker monitors. **This command WILL NOT remove the previous +tiebreaker monitor.** Remove the previous tiebreaker monitor yourself. + +Using "--set-crush-location" and not "ceph mon set_location" +------------------------------------------------------------ -If you are writing your own tooling for deploying Ceph, you can use a new -``--set-crush-location`` option when booting monitors, instead of running -``ceph mon set_location``. This option accepts only a single "bucket=loc" pair, eg -``ceph-mon --set-crush-location 'datacenter=a'``, which must match the -bucket type you specified when running ``enable_stretch_mode``. +If you write your own tooling for deploying Ceph, use the +``--set-crush-location`` option when booting monitors instead of running ``ceph +mon set_location``. This option accepts only a single ``bucket=loc`` pair (for +example, ``ceph-mon --set-crush-location 'datacenter=a'``), and that pair must +match the bucket type that was specified when running ``enable_stretch_mode``. +Forcing recovery stretch mode +----------------------------- -When in stretch degraded mode, the cluster will go into "recovery" mode automatically -when the disconnected data center comes back. If that doesn't work, or you want to -enable recovery mode early, you can invoke: +When in stretch degraded mode, the cluster will go into "recovery" mode +automatically when the disconnected data center comes back. If that does not +happen or you want to enable recovery mode early, run the following command: .. prompt:: bash $ ceph osd force_recovery_stretch_mode --yes-i-really-mean-it -But this command should not be necessary; it is included to deal with -unanticipated situations. +Forcing normal stretch mode +--------------------------- -When in recovery mode, the cluster should go back into normal stretch mode -when the PGs are healthy. If this doesn't happen, or you want to force the +When in recovery mode, the cluster should go back into normal stretch mode when +the PGs are healthy. If this fails to happen or if you want to force the cross-data-center peering early and are willing to risk data downtime (or have verified separately that all the PGs can peer, even if they aren't fully -recovered), you can invoke: +recovered), run the following command: .. prompt:: bash $ ceph osd force_healthy_stretch_mode --yes-i-really-mean-it -This command should not be necessary; it is included to deal with -unanticipated situations. But you might wish to invoke it to remove -the ``HEALTH_WARN`` state which recovery mode generates. +This command can be used to to remove the ``HEALTH_WARN`` state, which recovery +mode generates.