man: lvmlockd/clvmd notes about activation

activation details about lvmlockd and clvmd that were
previously in the generic lvchange -a section are now
moved to these man pages.

2 files changed, 53 insertions, 15 deletions

diff --git a/man/clvmd.8.in b/man/clvmd.8.in
index 9b9310d56..21f8c7dbf 100644
--- a/man/clvmd.8.in
+++ b/man/clvmd.8.in
@@ -154,6 +154,32 @@ This timeout will be ignored if you start \fBclvmd\fP with the \fB\-d\fP.
 .br
 Display the version of the cluster LVM daemon.
 .
+.SH NOTES
+.
+.SS Activation
+.
+In a clustered VG, clvmd is used for activation, and the following values are
+possible with \fBlvchange/vgchange -a\fP:
+.IP \fBy\fP|\fBsy\fP
+clvmd activates the LV in shared mode (with a shared lock),
+allowing multiple nodes to activate the LV concurrently.
+If the LV type prohibits shared access, such as an LV with a snapshot,
+an exclusive lock is automatically used instead.
+clvmd attempts to activate the LV concurrently on all nodes.
+.IP \fBey\fP
+clvmd activates the LV in exclusive mode (with an exclusive lock),
+allowing a single node to activate the LV.
+clvmd attempts to activate the LV concurrently on all nodes, but only
+one will succeed.
+.IP \fBly\fP
+clvmd attempts to activate the LV only on the local node.
+If the LV type allows concurrent access, then shared mode is used,
+otherwise exclusive.
+.IP \fBn\fP
+clvmd deactivates the LV on all nodes.
+.IP \fBln\fP
+clvmd deactivates the LV on the local node.
+.
 .SH ENVIRONMENT VARIABLES
 .TP
 .B LVM_CLVMD_BINARY
diff --git a/man/lvmlockd.8.in b/man/lvmlockd.8.in
index f01c69574..6e9b703cc 100644
--- a/man/lvmlockd.8.in
+++ b/man/lvmlockd.8.in
@@ -573,25 +573,37 @@ To place the lvmlock LV on a specific device, create the VG with only that
 device, then use vgextend to add other devices.
 
 
-.SS shared LVs
-
-When an LV is used concurrently from multiple hosts (e.g. by a
-multi\-host/cluster application or file system), the LV can be activated
-on multiple hosts concurrently using a shared lock.
-
-To activate the LV with a shared lock:  lvchange \-asy vg/lv.
-
-With lvmlockd, an unspecified activation mode is always exclusive, i.e.
-\-ay defaults to \-aey.
-
-If the LV type does not allow the LV to be used concurrently from multiple
-hosts, then a shared activation lock is not allowed and the lvchange
-command will report an error.  LV types that cannot be used concurrently
+.SS LV activation
+
+In a shared VG, activation changes involve locking through lvmlockd, and
+the following values are possible with lvchange/vgchange -a:
+
+.IP \fBy\fP|\fBey\fP
+The command activates the LV in exclusive mode, allowing a single host
+to activate the LV.  Before activating the LV, the command uses lvmlockd
+to acquire an exclusive lock on the LV.  If the lock cannot be acquired,
+the LV is not activated and an error is reported.  This would happen if
+the LV is active on another host.
+
+.IP \fBsy\fP
+The command activates the LV in shared mode, allowing multiple hosts to
+activate the LV concurrently.  Before activating the LV, the
+command uses lvmlockd to acquire a shared lock on the LV.  If the lock
+cannot be acquired, the LV is not activated and an error is reported.
+This would happen if the LV is active exclusively on another host.  If the
+LV type prohibits shared access, such as a snapshot, the command will
+report an error and fail.
+The shared mode is intended for a multi\-host/cluster application or
+file system.
+LV types that cannot be used concurrently
 from multiple hosts include thin, cache, raid, mirror, and snapshot.
-
 lvextend on LV with shared locks is not yet allowed.  The LV must be
 deactivated, or activated exclusively to run lvextend.
 
+.IP \fBn\fP
+The command deactivates the LV.  After deactivating the LV, the command
+uses lvmlockd to release the current lock on the LV.
+
 
 .SS recover from lost PV holding sanlock locks