5.3.3. Creating Volume Groups in a Cluster
You create volume groups in a cluster environment with the
vgcreate
command, just as you create them on a single node.
By default, volume groups created with CLVM on shared storage are visible to all computers that have access to the shared storage. It is possible, however, to create volume groups that are local, visible only to one node in the cluster, by using the
-c n
option of the vgcreate
command.
The following command, when executed in a cluster environment, creates a volume group that is local to the node from which the command was executed. The command creates a local volume named
vg1
that contains physical volumes /dev/sdd1
and /dev/sde1
.
# vgcreate -c n vg1 /dev/sdd1 /dev/sde1
You can change whether an existing volume group is local or clustered with the
-c
option of the vgchange
command, which is described in Section 5.3.8, “Changing the Parameters of a Volume Group”.
You can check whether an existing volume group is a clustered volume group with the
vgs
command, which displays the c
attribute if the volume is clustered. The following command displays the attributes of the volume groups VolGroup00
and testvg1
. In this example, VolGroup00
is not clustered, while testvg1
is clustered, as indicated by the c
attribute under the Attr
heading.
# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 19.88G 0
testvg1 1 1 0 wz--nc 46.00G 8.00M
For more information on the
vgs
command, see Section 5.3.5, “Displaying Volume Groups”Section 5.8, “Customized Reporting for LVM”, and the vgs
man page.