LVM

What is and how to use LVM?

RTFM; LVM HOWTO

How to use lvm to use multiple disk as one logical file share?

• Pv, vg and lv setup

  pvcreate /dev/sda /dev/sdb /dev/sdc
  
  vgcreate data1 /dev/sda /dev/sdb /dev/sdc
  
  vgdisplay data1 | grep "Total PE"
  
  lvcreate -l 155008 --name store data1
  
  

• Make filesystem:

  mkfs.ext3 -m 0 -O sparse_super /dev/lvm_ed/store 
  

How to add a disk to an existing lvm setup?

• Initialize the disk for use with lvm

  pvcreate /dev/sde
  

• Extend vg

vgextend data /dev/sde

• Extend lv

use vgdisplay to find available PEs and extend lv accordingly.

vgdisplay data | grep "Free  PE"
lvextend -l +59618 /dev/data/media

• Extend file system

umount /dev/data/media
e2fsck -f /dev/data/media
resize2fs /dev/data/media

• mount the device

How to remove a disk from an existing lvm setup?

• unmount the lvm device

• make filesystem smaller

e2fsck -f /dev/lvm_ed/store

resize2fs /dev/lvm_ed/store 350G 

• Reduce lv

  lvreduce -L 350g /dev/lvm_ed/store
  
  
  

• Move data away from the physical disk

  pvmove  /dev/sde		
  
  
  

• Reduce vg

vgreduce lvm_ed /dev/sde

• mount

on /dev/lvm_ed/store to 91750400 (4k) blocks.

resize2fs device newSize