vgextend.1m (2010 09)

v
vgextend(1M) vgextend(1M)
If the specified physical volume group does not exist, it is created, thus provid-
ing a means for creating new physical volume groups after the volume group
has been created. Another way to extend or add a physical volume group is to
edit the /etc/lvmpvg file as described in vgcreate (1M). See lvmpvg (4) for
format details.
-x extensibility Set allocation permission for additional physical extents on the physical
volume specified by pv_path . extensibility can have one of the following
values:
y Allow allocation of additional physical extents on the physical volume.
n Prohibit allocation of additional physical extents on the physical volume.
Logical volumes residing on the physical volume can still be accessed.
-z sparepv This option is only applicable on volume groups version 1.0. Versions 2.0 or
higher do not support sparing. This option requires the installation of the
optional HP MirrorDisk/UX software. It allows you to mark the physical
volume(s) specified by pv_path to be either a spare physical volume or a regu-
lar, non-spare physical volume. (A spare physical volume can be used to
replace an existing physical volume within a volume group when mirroring is
in effect, in the event the existing physical volume fails.) sparepv can have
one of the following values:
y The physical volume(s) will be used as spare(s). No physical extents
from a spare physical volume will be available as part of the "free" pool of
extents in the volume group. The spare physical volume(s) will only be
used in the event of another physical volume within this volume group
becomes unavailable (fails).
n The physical volume(s) will be used as regular, non-spare members of
the volume group. This is the default.
Alternate Links (PVLinks)
In this release of HP-UX, LVM continues to support Alternate Links to a device to allow continued access
to the device, if the primary link fails. This multiple link or multipath solution increases data availabil-
ity, but does not allow the multiple paths to be used simultaneously.
There is a new feature introduced in the Mass Storage Subsystem on this version of HP-UX that also sup-
ports multiple paths to a device and allows access to the multiple paths simultaneously. The Mass
Storage Subsystem will balance the I/O load across the valid paths. This new multi-path behavior is
enabled and disabled through the use of the scsimgr command. See scsimgr(1M) for details.
It is no longer required or recommended to configure LVM with alternate links. However, it is possible to
maintain the traditional LVM behavior. To do so, both of the following criteria must be met:
• Only the legacy device special file naming convention is used in the volume group configuration.
• The scsimgr command is used to disable the Mass Storage Subsystem multipath behavior.
Shared Volume Group Considerations
For volume group version 1.0 and 2.0,
vgextend cannot be used if the volume group is activated in
shared mode. For volume groups version 2.1 (or higher), vgextend can be performed when activated in
either shared, exclusive, or standalone mode.
Note that the
lvmpud daemon must be running on all the nodes sharing a volume group activated in
shared mode. See lvmpud(1M).
If the
-g pvg_name option is used, the /etc/lvmpvg file is changed only on the system where the com-
mand is issued (the server).
vgextend can add alternate PV links only on the server node; alternate links cannot be added on client
nodes.
When a PV is added to the volume group, the PV path passed as the
vgextend argument is added into
/etc/lvmtab_p on the server. However, on the clients, it is always the PV persistent device special
file that is added into /etc/lvmtab_p. /etc/lvmtab_p is automatically updated on the nodes shar-
ing the volume group.
2 Hewlett-Packard Company − 2 − HP-UX 11i Version 3: September 2010