How to construct LVM system

What is LVM?
Combine physical volumes in a volume group, and divided it in to several logical volumes


Consequences
Partitioning (fdisk) --> Create physical volume (pvcreate) --> Create volume group (vgcreate) --> Create logical volume (lvcreate)  --> Formatting (mkfs) --> Mount

Process is similar with adding new hard disk in CentOS


Cautions
* select volume type 'LVM'


ex)
pvcreate  /dev/sdb1
pvcreate  /dev/sdc1
vgcreate  myVG  /dev/sdb1  /dev/sdc1
vgdisplay
lvcreate  --size 1g  --name  myLG1  myVG
lvcreate  --size 3g  --name  myLG2  myVG
lvcreate  --extents 100%FREE  --name  myLG3  myVG