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

19
Total Spare PVs in use 0
VG Version 1.0
VG Max Size 889600m
VG Max Extents 222400
There are 12799 extents allocated on this physical volume.
2. Use online vgmodify to review the effect of the change in disk size.
# vgmodify –r -a -E vg1
"/dev/rdisk/disk43" size changed from 52428800 to 71687369kb
"/dev/rdisk/disk43" size is limited by the maximum extents per PV
to 56934400.
An update to the Volume Group IS required
Review complete. Volume group not modified
3. Use online vgmodify to change the disk size.
# vgmodify -a -E vg1
"/dev/rdisk/disk43" size changed from 52428800 to 71687369kb
"/dev/rdisk/disk43" size is limited by the maximum extents per PV
to 56934400.
4. Verify the change.
# vgdisplay vg1
--- Volume groups ---
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 13900
VGDA 2
PE Size (Mbytes) 4
Total PE 13900
Alloc PE 12799
Free PE 1101
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0
VG Version 1.0
VG Max Size 889600m
VG Max Extents 222400
The entire increase in disk space is not made available for use by LVM. This is because of the
max_PE value, which is set to 13900. Only part of the disk space (54 GB out of 68 GB) was
used to increase the number of physical extents allocated on the disk from 12799 to 13900.
To fully utilize the 68 GB disk space, you must use offline vgmodify and modify the volume
group configuration parameters.
Performing online DLE when none of the additional disk space can be allocated
This example assumes you have a 50 GB disk belonging to volume group vg1 that has its max_PE per
PV value set to 12799. The disk size was increased to 63 GB using the relevant disk utilities.
1. Review current volume group parameters.
# vgdisplay vg1
--- Volume groups ---