LVM in Linux

How to extend LVM, if volume group has enough free space available :

$lvextend -L +100G /dev/mapper/vg_01-home -r

-r means you don't need to use the following command next
$resize2fs /dev/mapper/vg_01-home


How to extend LVM, if volume group has not enough free space available :

• Add extra disk
• Increase the Volume group 
• Increase the Logical Volume group

$lsblk -l  OR fdisk -l
$pvcreate /dev/sde
$vgextend vg_01 /dev/sde
$lvextend -L +100G /dev/mapper/vg_01-home
$resize2fs /dev/mapper/vg_01-home


How to create LVM from scratch?

$pcreate /dev/sdb
$vgcreate vg01 /dev/sdb
$pvdisplay
$vgdisplay
$lvcreate -L 1G -n lvmvol1 vg01
$lvs
$vgs
$pvs
$mkfs.ext4 /dev/vg01/lvmvol1
$mount -t ext4 /dev/vg01/lvmvol1 /mnt/lvmvol1
$lvresize -L +1G -n /dev/vg01/lvmvol1

###filesystem path can be either of them
/dev/vg01/lvmvol1
/dev/mapper/vg01/lvmvol1