LVM Volume Group Dynamic LUN Expansion (DLE) and Contraction (DLC) (September 2009)

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VG Name /dev/vg1
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 1
Open LV 0
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 12799
VGDA 2
PE Size (Mbytes) 4
Total PE 12799
Alloc PE 12799
Free PE 0
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0
VG Version 1.0
VG Max Size 819136m
VG Max Extents 204784
There are 12799 extents allocated on this physical volume.
2. Use online vgmodify to review the change in disk size.
# vgmodify –r -a -E vg1
An update to the Volume Group is NOT required
Review complete. Volume group not modified
The output indicates that the volume group does not require an update. This is because the
number of extents allocated on the PV is already at the max_PE value of 12799; you cannot
add more extents to this PV without changing the max_PE value. To change the max_PE
value, you must use offline vgmodify (see the examples on physical extent renumbering).
Offline DLE examples
The fo
llowing example assumes the volume group is already activated. This is not a requirement as
vgmodify activates the volume group if needed. If vgmodify does activate the volume group, it
deactivates it before completion.
Performing DLE when only some disk space can be allocated
1. Run vgmodify –v –r vgname. Any disks that were resized since pvcreate was run on
them are reported as follows:
/dev/rdsk/c0t0d0 size changed from 16777216 to 100000000kb
If there is insufficient space to allocate all the disk space on any device, a message similar to
the following appears:
/dev/rdsk/c0t4d2 Warning: Max_PE_per_PV for the volume group (4348)
too small for this PV (24413).
Using only 4348 PEs from this physical volume.
If you want to change the volume group configuration parameters, follow the guidelines in the
Volume group configuration changes se
ction.
2. During a maintenance window, deactivate the volume group.
3. Use vgmodify to review the configuration.
# vgmodify -r -v vg04