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author | David Teigland <teigland@redhat.com> | 2017-01-18 14:40:32 -0600 |
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committer | David Teigland <teigland@redhat.com> | 2017-02-07 10:38:30 -0600 |
commit | 0a61ea395f11424034b1d81b10710655fc6bf81c (patch) | |
tree | 8cfcf19a229d0d3a7d2caef4b466539e936847c4 | |
parent | e61f84cd1fc5d087477c5ffd5ebbd4d2d3b6fdd0 (diff) | |
download | lvm2-0a61ea395f11424034b1d81b10710655fc6bf81c.tar.gz |
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.
-rw-r--r-- | man/clvmd.8.in | 26 | ||||
-rw-r--r-- | man/lvmlockd.8.in | 42 |
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 |