====== LVM 설정예제 2 ======

===== Demonstration =====
  - Start by looking at our existing disks <code>
cat /proc/scsi/
dmesg |grep sd
</code>
  - Next, partition the new disks using fdisk <code>
fdisk /dev/sdb
</code>
    - p to Print the existing table (should be blank)
    - n to create a new partition
    - t to change partition system ID to 8e (Linux LVM)
    - w to write new table to disk
  - Repeat for /dev/sdc
  - Create the physical volumes <code>
pvcreate /dev/sdb1
pvcreate /dev/sdc1
</code>
  - NOTE: You can create multiple PVs on a single disk, but it is not recommended. Show existing Physical Volumes <code>
pvscan
</code>
  - Show Volume Groups <code>
vgscan (should return nothing)
</code>
  - Create a Volume Group from the Physical Volumes <code>
vgcreate opt_vg /dev/sdb1 /dev/sdc1
</code>
  - NOTE: You can specify PE size in vgcreate. Default is 4M. You'd use larger PE sizes for LVs greater than 256G. 65K PEs per LV. 
  - Show Volume Groups <code>
vgscan (now shows the VG we created)
</code>
  - Display information about the VG <code>
vgdisplay 
</code>
  - Create a Logical Volume within the VG <code>
lvcreate -l num_of_extents -n opt_lv opt_vg
lvcreate -L 100M -n opt_lv opt_vg
lvcreate -L 100M -n opt_lv -i num_stripes opt_vg
lvcreate -L 100M -n opt_lv opt_vg [PhysicalVolumePath]
</code>
  - Display information about the LV <code>
lvdisplay
lvdisplay -m (Show maps. Compare striped vs un-striped)
</code>
  - Create a mount point <code>
mkdir /opt/foo1
mkdir /opt/striped
</code>
  - Create a filesystem <code>
mkfs.ext3 /dev/opt_vg/opt_lv
mkfs.ext3 /dev/opt_vg/striped_lv
</code>
  - Mount the filesystems <code>
mount /dev/opt_vg/opt_lv
df -h 
</code>

===== Growing a Filesystem =====
 
==== Grow an EXT2/3 filesystem (with unmount) ====

  - Unmount the FS <code>
umount /mnt/lvm_filesystem
</code>
  - Extend the LV <code>
lvresize -l +50 /dev/opt_vg/opt_lv
lvresize -L +200M /dev/opt_vg/opt_lv
fsck the filesystem 
e2fsck -f /dev/opt_vg/opt_lv
</code>
  - Resize the filesystem <code>
resize2fs /dev/opt_vg/opt_lv
</code>
  - Remount the filesystem <code>
mount -t ext3 /dev/opt_vg/opt_lv /mnt/lvm_filesystem
</code>

==== Grow an EXT2/3 filesystem (without unmount) ====
  - Extend the LV <code>
lvresize -l +50 /dev/opt_vg/opt_lv
lvresize -L +200M /dev/opt_vg/opt_lv
</code>
  - Grow the filesystem <code>
ext2online /mnt/lvm_filesystem (using mount path)
ext2online /dev/opt_vg/opt_lv (using device)
</code>

==== Grow a ReiserFS filesystem ====
  - Create a ReiserFS on /dev/opt_vg/striped_lv <code>
mkreiserfs /dev/opt_vg/striped_lv
</code>
  - Mount the FS <code>
df -h
lvresize -L +50M /dev/opt_vg/striped_lv
resize_reiserfs -f /dev/opt_vg/striped_lv
df -h
</code>
  - Add a Physical Volume to a VG <code>
vgextend vgname /path/to/PV
</code>