1CLVMD(8) System Manager's Manual CLVMD(8)
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6 clvmd — cluster LVM daemon
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9 clvmd [-C] [-d [value]] [-E lock_uuid] [-f] [-h] [-I cluster_manager]
10 [-R] [-S] [-t timeout] [-T start_timeout] [-V]
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13 clvmd is the daemon that distributes LVM metadata updates around a
14 cluster. It must be running on all nodes in the cluster and will give
15 an error if a node in the cluster does not have this daemon running.
16 Also see lvmlockd(8) for a newer method of using LVM on shared storage.
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20 -C
21 Only valid if -d is also specified. Tells all clvmds in a clus‐
22 ter to enable/disable debug logging. Without this switch, only
23 the local clvmd will change its debug level to that given with
24 -d.
25 This does not work correctly if specified on the command-line
26 that starts clvmd. If you want to start clvmd and enable clus‐
27 ter-wide logging then the command needs to be issued twice, eg:
28 clvmd
29 clvmd -d2
30 -d [value]
32 Set debug logging level. If -d is specified without a value
33 then 1 is assumed. Value can be:
34 0 — Disabled
35 1 — Sends debug logs to stderr (implies -f)
36 2 — Sends debug logs to syslog(3)
37 -E lock_uuid
39 Pass lock uuid to be reacquired exclusively when clvmd is
40 restarted.
41 -f
43 Don't fork, run in the foreground.
44 -h
46 Show help information.
47 -I cluster_manager
49 Selects the cluster manager to use for locking and internal com‐
50 munications. As it is quite possible to have multiple managers
51 available on the same system you might have to manually specify
52 this option to override the search.
53 By default, omit -I is equivalent to -Iauto. Clvmd will use the
55 first cluster manager that succeeds, and it checks them in a
56 predefined order cman, corosync, openais. The available man‐
57 agers will be listed by order as part of the clvmd -h output.
58 -R
60 Tells all the running instance of clvmd in the cluster to reload
61 their device cache and re-read the lvm configuration file
62 lvm.conf(5). This command should be run whenever the devices on
63 a cluster system are changed.
64 -S
66 Tells the running clvmd to exit and reexecute itself, for exam‐
67 ple at the end of a package upgrade. The new instance is
68 instructed to reacquire any locks in the same state as they were
69 previously held. (Alternative methods of restarting the daemon
70 have the side effect of changing exclusive LV locks into shared
71 locks.)
72 -t timeout
74 Specifies the timeout for commands to run around the cluster.
75 This should not be so small that commands with many disk updates
76 to do will fail, so you may need to increase this on systems
77 with very large disk farms. The default is 60 seconds.
78 -T start_timeout
80 Specifies the start timeout for clvmd daemon startup. If the
81 daemon does not report that it has started up within this time
82 then the parent command will exit with status of 5. This does
83 NOT mean that clvmd has not started! What it means is that the
84 startup has been delayed for some reason; the most likely cause
85 of this is an inquorate cluster though it could be due to lock‐
86 ing latencies on a cluster with large numbers of logical vol‐
87 umes. If you get the return code of 5 it is usually not neces‐
88 sary to restart clvmd it will start as soon as that blockage has
89 cleared. This flag is to allow startup scripts to exit in a
90 timely fashion even if the cluster is stalled for some reason.
91 The default is 0 (no timeout) and the value is in seconds. Don't
93 set this too small or you will experience spurious errors. 10 or
94 20 seconds might be sensible.
95 This timeout will be ignored if you start clvmd with the -d.
97 -V
99 Display the version of the cluster LVM daemon.
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102 Activation
103 In a clustered VG, clvmd is used for activation, and the following val‐
104 ues are possible with lvchange/vgchange -a:
105 y|sy clvmd activates the LV in shared mode (with a shared lock),
107 allowing multiple nodes to activate the LV concurrently. If the
108 LV type prohibits shared access, such as an LV with a snapshot,
109 an exclusive lock is automatically used instead. clvmd attempts
110 to activate the LV concurrently on all nodes.
111 ey clvmd activates the LV in exclusive mode (with an exclusive
113 lock), allowing a single node to activate the LV. clvmd
114 attempts to activate the LV concurrently on all nodes, but only
115 one will succeed.
116 ly clvmd attempts to activate the LV only on the local node. If
118 the LV type allows concurrent access, then shared mode is used,
119 otherwise exclusive.
120 n clvmd attempts to deactivate the LV on all nodes.
122 ln clvmd attempts to deactivate the LV on the local node.
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126 LVM_CLVMD_BINARY
127 The CLVMD binary to use when clvmd restart is requested.
128 Defaults to /usr/clvmd.
129 LVM_BINARY
131 The LVM2 binary to use. Defaults to /usr/lvm.
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134 /usr/clvmd
135 /usr/lvm
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138 syslog(3), lvm.conf(5), lvm(8), lvmlockd(8), lvmsystemid(7)
139Red Hat Inc LVM TOOLS 2.02.183(2) (2018-12-07) CLVMD(8)