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
paging
jfs logs
raw devices
boot


Mirroring

2PP       1 LP
3PP       1 LP

Striping

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

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Disk Management.

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


#lspv
<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
/etc/vg/vg-id
/dev/hdiskX
/dev/VGname
/dev/LVname
/dev/filesystem


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