How do you extend a LV? For example, How do you expand /var file system with additional 2GB space?

How do you extend a LV? For example, How do you expand /var file system with additional 2GB space?

• Check which logical volume (LV) holds the  /var file system using df –h
• Now, find out this particular LV belongs to which VG using lvdisplay <lv_name>
• Check the free space available in that Volume Group (VG) using vgdisplay <vgname>. Look for "Free PE / Space" line in the ouput.
• If the free space available in VG, now you can expand the LV using lvextend –L +2G <lv_name>. Now, Logical Volume has been expanded. Now we have to expand the file system using resize2fs /var. All these can be done in online without unmounting the filesystems.