From 301d53a3c768d3a6c1340acc30ba6a13aac0cb81 Mon Sep 17 00:00:00 2001 From: John Spray Date: Mon, 3 Jul 2017 14:46:47 +0100 Subject: [PATCH] doc/mon: clean up `mds fail`/`mds deactivate` descriptions Fixes: http://tracker.ceph.com/issues/20424 Signed-off-by: John Spray --- doc/cephfs/administration.rst | 22 +++++++++++++++++----- src/mon/MonCommands.h | 6 ++++-- 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/doc/cephfs/administration.rst b/doc/cephfs/administration.rst index 23bd5fc6a99..f4976cfa2df 100644 --- a/doc/cephfs/administration.rst +++ b/doc/cephfs/administration.rst @@ -81,17 +81,29 @@ These commands act on specific mds daemons or ranks. :: - mds fail -This command deactivates an MDS causing it to flush its entire journal to -backing RADOS objects and close all open client sessions. Deactivating an MDS -is primarily intended for bringing down a rank after reducing the number of -active MDS (max_mds). +Mark an MDS daemon as failed. This is equivalent to what the cluster +would do if an MDS daemon had failed to send a message to the mon +for ``mds_beacon_grace`` second. If the daemon was active and a suitable +standby is available, using ``mds fail`` will force a failover to the standby. + +If the MDS daemon was in reality still running, then using ``mds fail`` +will cause the daemon to restart. If it was active and a standby was +available, then the "failed" daemon will return as a standby. :: mds deactivate +Deactivate an MDS, causing it to flush its entire journal to +backing RADOS objects and close all open client sessions. Deactivating an MDS +is primarily intended for bringing down a rank after reducing the number of +active MDS (max_mds). + +Use ``mds deactivate`` in conjunction with adjustments to ``max_mds`` to +shrink an MDS cluster. See :doc:`/cephfs/multimds` + :: tell mds. diff --git a/src/mon/MonCommands.h b/src/mon/MonCommands.h index e5e3cd98bef..973b6eabc7b 100644 --- a/src/mon/MonCommands.h +++ b/src/mon/MonCommands.h @@ -301,7 +301,8 @@ COMMAND("mds compat show", "show mds compatibility settings", \ "mds", "r", "cli,rest") COMMAND_WITH_FLAG("mds stop name=who,type=CephString", "stop mds", \ "mds", "rw", "cli,rest", FLAG(DEPRECATED)) -COMMAND("mds deactivate name=who,type=CephString", "stop mds", \ +COMMAND("mds deactivate name=who,type=CephString", + "clean up specified MDS rank (use with `set max_mds` to shrink cluster)", \ "mds", "rw", "cli,rest") COMMAND_WITH_FLAG("mds set_max_mds " \ "name=maxmds,type=CephInt,range=0", \ @@ -320,7 +321,8 @@ COMMAND("mds set_state " \ "name=state,type=CephInt,range=0|20", \ "set mds state of to ", "mds", "rw", "cli,rest") COMMAND("mds fail name=who,type=CephString", \ - "force mds to status failed", "mds", "rw", "cli,rest") + "Mark MDS failed: trigger a failover if a standby is available", + "mds", "rw", "cli,rest") COMMAND("mds repaired name=rank,type=CephString", \ "mark a damaged MDS rank as no longer damaged", "mds", "rw", "cli,rest") COMMAND("mds rm " \ -- 2.39.5