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

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# pvdisplay /dev/dsk/c6t0d0
--- Physical volumes ---
PV Name /dev/dsk/c6t0d0
VG Name /dev/vg04
PV Status available
Allocatable yes
VGDA 2
Cur LV 0
PE Size (Mbytes) 4
Total PE 1220
Free PE 1220
Allocated PE 0
Stale PE 0
IO Timeout (Seconds) default
Autoswitch On
Proactive Polling On
The Total PE is now 1220.
Online and offline DLC examples
The exampl
es in this section are the same for both online and offline, and assume the volume group is
already activated. In offline mode, 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.
Also, in offline mode, the volume group can be active for review mode, but must be deactivated
during the actual vgmodify operation. In online mode, the volume group must be active during the
actual operation.
Performing DLC on a physical volume with free extents
This example assumes a volume group that has a disk of size 73 GB, and you want to determine if
you can contract the physical volume can to 50 GB from the LVM end.
1. Review the current configuration.
# vgdisplay vg01
--- Volume groups ---
VG Name /dev/vg01
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 1
Open LV 1
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 17501
VGDA 2
PE Size (Mbytes) 4
Total PE 17501
Alloc PE 10000
Free PE 7501
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0
VG Version 1.0
VG Max Size 1120064m
VG Max Extents 280016
# pvdisplay –v /dev/dsk/c4t2d0
--- Physical volumes ---
PV Name /dev/dsk/c4t2d0