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

40
Summary 896 4096
Physical Extent zero is not free on all PVs. You will not achieve
these values until the first extent is made free (see pvmove(1M))
on all the following disks:
/dev/rdsk/c0t0d0
/dev/rdsk/c0t1d0
/dev/rdsk/c11t3d0
Volume Group optimized settings (PEs renumbered lower):
max_pv(-p) max_pe(-e) Disk size (Mb)
7 65535 262144
* Entries deleted for brevity
19 26364 105460
20 25084 100340
21 23804 95220
22 22780 91124
23 21756 87028
24 20988 83956
* Entries deleted for brevity
36 13820 55284
With –n we can place up to 23 disks of 90 GB in size, but we must free up the first extent on
three disks. The need was for at least 20 disks so any entries between the 20 and 24 will
suffice. The example uses 23.
2. Free up the first extent on all four disks – note: keeping the extent on the same disk.
# pvmove /dev/dsk/c0t0d0:0 /dev/dsk/c0t0d0
Transferring logical extents of logical volume "/dev/vg02/lvol1"...
Physical volume "/dev/dsk/c0t0d0" has been successfully moved.
Volume Group configuration for /dev/vg02 has been saved in
/etc/lvmconf/vg02.conf
# pvmove /dev/dsk/c0t1d0:0 /dev/dsk/c0t1d0
Transferring logical extents of logical volume "/dev/vg02/lvol2"...
Physical volume "/dev/dsk/c0t1d0" has been successfully moved.
Volume Group configuration for /dev/vg02 has been saved in
/etc/lvmconf/vg02.conf
# pvmove /dev/dsk/c0t3d0:0 /dev/dsk/c0t3d0
Transferring logical extents of logical volume "/dev/vg02/lvol3"...
Physical volume "/dev/dsk/c0t3d0" has been successfully moved.
Volume Group configuration for /dev/vg02 has been saved in
/etc/lvmconf/vg02.conf
3. Run vgmodify in review mode.
# vgmodify -r -n -p 23 -e 21756 vg02
Current Volume Group settings:
Max LV 255
Max PV 16
Max PE per PV 5119
PE Size (Mbytes) 4
VGRA Size (Kbytes) 736
The current and new Volume Group parameters differ.
An update to the Volume Group IS required
New Volume Group settings:
Max LV 255
Max PV 23
Max PE per PV 21756