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Diffstat (limited to 'man/lvmlockd.8.in')
| -rw-r--r-- | man/lvmlockd.8.in | 42 |
1 files changed, 27 insertions, 15 deletions
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 |