===== Various Information =====
8e is the partition type for Linux LVM
if you get "Incorrect metadata area header checksum" check the filters in /etc/lvm.conf


==== LVM1 Extent Sizes ====
Only applies to LVM1

  * 4 4mB extents == 16mB
  * There is a kernel limit of 65,536 physical extents per logical volume
  * The -s option to vgcreate selects the extent size
  
^  Extent Size  ^  Max Logical Volume Size  ^
|  4mB  |  256gB  |
|  8mB  |  512gB  |
|  16mB  |  1024gB  |
|  32mB  |  2048gB  |


    
===== Commands =====

  pvcreate /dev/sda1
  pvcreate /dev/sda2
  vgcreate -s 32 vg /dev/sda1
  vgextend vg /dev/sda2
  lvcreate -L10G -nhome vg
  lvextend -L+5G /dev/vg/home
  mke2fs -j /dev/vg/home


====Remove a physical volume====
  * To move all logical extents off of /dev/md2 to other available drives
  * pvmove -v /dev/md2
  * vgreduce vg /dev/md2

====Various commands====
  lvdisplay - Shows all logical volumes

====On-Line Resizing ext3====
  To resize an ext3 volume online
  To extend the /dev/vg/storage volume by 1Gigabyte
  lvextend -L+1G /dev/vg/storage
  and then resize it
  resize2fs /dev/vg/storage
====Creating a snapshot ====
  /etc/init.d/dmeventd start
  lvcreate -L 5G  -s -n vmsnap /dev/vg/storage
  OriginalLogicalVolume[Path] [PhysicalVolumePath...]
=== Received the error below once when creating a snapshot ===
==Had to start dmeventd ===
  Unable to start dmeventd.
  Unable to start dmeventd.
  storage-snapStorage: event registration failed: No such process
  storage/snapshot0: snapshot segment monitoring function failed.
  Logical volume "snapStorage" created
  
  
==== To move logical partitions from one drive to another ====
Will need the dm_mirror module loaded
  
Create logical partitions on drive b
    pvcreate /dev/sda{1,2}
    vgextend storage /dev/sda{1,2}
Disable allocation on the old PV
  pvchange  -x n /dev/sdb2
Move the extents over
    pvmove -v /dev/sdb2
  
vgreduce storage /dev/sdb2 vg
    
===== Troubleshooting =====
Power went out, and the mail server failed to start back up, one of the partitions had gotten lost, it showed in the partition table as free space, recreated the partition, rebooted and it worked.

Was also looking into doing
  * pvcreate --uuid uuid --restorefile /etc/lvm/backup/prime-vg prime /dev/sda6
====If one of the partitions is down in a volume Group ====
  * vgdisplay --partial --verbose
  
==== To deactivate a VG, such as on an external drive ====
  * umount any logical volumes
  * deactivate any logical volumes
    * lvchange -a n /dev/server_backups/netware
  * deactivate volume group
    * vgchange -a n server_backups
    
==== Unplugged a usb drive ====
Was having problems after plugging it back in
  * vgchange -a n server_backups
  * vgchange -a y server_backups
  * vgscan

=====Links=====
  * http://www.novell.com/coolsolutions/appnote/19386.html
  * http://kbase.redhat.com/faq/docs/DOC-3335
  * http://www.ibm.com/developerworks/library/l-lvm2/?ca=dgr-lnxw02LinuxLVM2&S_TACT=105AGX59&S_CMP=GR