Logical Volume Manager

........./Updation in progress

Physical Volume : hard disk

PV /dev/hdisk0

Volume Groups

Regular : has 32 PV
Big     : has 128 PV

PP  : Are the smallest unit of Storage.
LP  : Is a pointer to PP,

LV is grouping of LP.

file sys
jfs logs
raw devices


2PP       1 LP
3PP       1 LP


Data is stripped and is written
accros multiple disks in the
striped logical volume


Disk Management.

#uname -m
First Eight are Machine ID
<Machine Id><Type>

<machine id><date time of volume configured>

VGDA (Volue Group Descriptor Area)

Header Time stamp : Timestamp of last VG modification
Physical Volume List
Logical Volume List
Physical Partition Map

Most important data structure of LVM
All the administrative information about the Volume group

VGSA  (Volume Group Status Area)
Tracks the state of mirrored copies

LVCB (Logical Volume Control Block)

Files where the LVM is stored