HP-UX 11i v3 vgmodify.1m (2011 09) Manpage

v
vgmodify(1M) vgmodify(1M)
• To expand the LVM configuration data to its maximum size, it may be necessary to reallocate the first
physical extent from each physical volume from user to LVM configuration data. This will only be pos-
sible if the first extent is made free (see pvmove (1M)) and PE renumbering is enabled via the
-n
option.
• The LVM configuration data size is limited to the volume group extent size. Therefore, a maximum of
one physical extent from each physical volume can be reallocated from user data regardless of how
many times
vgmodify is used on the volume group.
• The attributes of an
lvmconf file can be viewed using the
-v option of vgcfgrestore (see
vgcfgrestore (1M)).
• To take advantage of a physical volume size increase, it may be necessary to run
vgmodify to
increase the maximum number of physical extents for the volume group. For a deactivated volume
group, the
vgmodify command will implicitly consider the physical volume size increase. But for an
activated volume group, the -E option should be used for
vgmodify to consider the physical volume
size increase.
• In general, a smaller number of physical volumes allows a larger number of physical extents. Like-
wise, a larger number of physical volumes constraints to a smaller number of physical extents.
• For a deactivated volume group, the detection of physical volume size changes (LUN size expansion or
contraction) is automatic, with the handling taking place unless the
-r or -t options have been used.
• For an activated volume group, the detection of a physical volume size increase (LUN size expansion)
is not automatic. Instead, the
-E option should be used for vgmodify to detect and handle the physi-
cal volume size increase.
• When used with the
-r option, the -C option reports if the physical volume can be prepared for con-
traction to the specified size. If not, it displays the number of extents that need to be freed up on phy-
sical volume before it can be prepared for contraction to the specified size. In addition, it reports the
smallest size to which the physical volume can be prepared for contraction without performing any
pvmove operations on it, and the smallest size to which the physical volume can be prepared for con-
traction after compacting all the allocated physical extents on it by moving them up.
• The changing of physical volume type (boot to non-boot or vice verse) is selected via the
-B option and
by specifying a list of physical volumes. Otherwise, no physical volume type changes are performed.
• For an activated volume group, the
-B, -C, and the
-E options are mutually exclusive, since the phy-
sical volume list for the
-B option is the list of the physical volumes to change from boot to non-boot or
vice versa. The physical volume list for the -E and -C options is the list of physical volumes to con-
sider for increase and decrease in disk size, respectively.
• When used with the
-a option, the lower limit of max_pv is one more than the highest pvkey in use.
When holes exist in the used pvkey ranges due to previously executed
vgreduce operations and
max_pv needs to be reduced below this lower limit in order to compact the pvkeys , the volume group
will need to be deactivated before running vgmodify. The possible set of values for max_pv when
the volume group is activated can be obtained using the
-a option along with -t.
Remarks for Volume Groups Version 2.0 and Higher
• This command can be run on volume groups version 2.0 and higher that are activated in standalone or
exclusive mode. It can also run on volume groups activated in shared mode if they are 2.1 or higher.
In the case of a shared volume group, the command must be issued on the server and the
lvmpud
daemon must be running on all the nodes sharing the volume group. See lvmpud (1M).
• If
vgmodify is interrupted while it is reconfiguring the physical volumes, or if the command fails,
then the volume group is left in a consistent state (no special recovery is needed). To retry the vgmo-
dify operation, run the vgmodify command with the desired options, and LVM will continue with
the reconfiguration.
•
vgmodify will fail if the volume group has a cluster lock physical volume.
• The detection of a physical volume size increase (LUN size expansion) is not automatic. Instead, the
-E option should be used to detect and handle the physical volume size increase.
• When used with the
-r option, the -C option reports if the physical volume can be prepared for con-
traction to the specified size. If not, it displays the number of extents that need to be freed up on phy-
sical volume before it can be prepared for contraction to the specified size. In addition, it reports the
smallest size to which the physical volume can be prepared for contraction by removing all free extents
on the physical volume.
HP-UX 11i Version 3: September 2011 − 5 − Hewlett-Packard Company 5