HP-UX System Administrator's Guide: Logical Volume Management HP-UX 11i v3 (B3921-90053 September 2011) Transform used: ESS version 2.2

ManualsBrandsHP ManualsSoftwareHP-UX 11i Volume Management (LVM/VxVM) Software

Contents

1 Introduction...............................................................................................8

LVM Features...........................................................................................................................8

LVM Architecture.......................................................................................................................9

Physical versus Logical Extents..................................................................................................10

LVM Volume Group Versions....................................................................................................11

LVM Device File Usage............................................................................................................12

Legacy Device Files versus Persistent Device Files....................................................................12

Cluster-wide Device Special Files..........................................................................................13

Naming Conventions for LVM..............................................................................................13

Device Number Format.......................................................................................................15

Version 1.0 Device Number Format..................................................................................16

Version 2.x Device Number Format..................................................................................16

LVM Disk Layout.....................................................................................................................16

Boot Data Reserved Area....................................................................................................16

Logical Interface Format Area..............................................................................................17

Physical Volume Reserved Area............................................................................................17

Volume Group Reserved Area..............................................................................................17

User Data Area.................................................................................................................17

LVM Limitations.......................................................................................................................18

Shared LVM...........................................................................................................................18

2 Configuring LVM......................................................................................20

Planning Your LVM Configuration..............................................................................................20

Setting Up Different Types of Logical Volumes.............................................................................20

Setting Up Logical Volumes for Raw Data Storage..................................................................20

Setting Up Logical Volumes for File Systems...........................................................................21

File System Logical Volume Guidelines.............................................................................22

Setting Up Logical Volumes for Swap....................................................................................22

Swap Logical Volume Guidelines.....................................................................................22

Setting Up Logical Volumes for Dump...................................................................................23

Dump Logical Volume Guidelines....................................................................................23

Setting Up Snapshot Logical Volumes for Backup....................................................................23

Planning for Availability..........................................................................................................24

Increasing Data Availability Through Mirroring......................................................................24

Mirror Write Behavior Control.........................................................................................24

Allocation Policy.......................................................................................................24

Scheduling Policy.....................................................................................................25

Synchronization Policy...............................................................................................25

Synchronizing a Mirrored Logical Volume.........................................................................26

Increasing Disk Redundancy Through Disk Sparing.................................................................27

Increasing Hardware Path Redundancy Through Multipathing..................................................28

Setting Up Multipathing to a Physical Volume (LVM PVlinks)................................................28

Planning for Performance.........................................................................................................29

General Performance Factors...............................................................................................29

Memory Usage.............................................................................................................29

CPU Usage..................................................................................................................29

Disk Space Usage.........................................................................................................29

Internal Performance Factors................................................................................................29

Scheduling Policy..........................................................................................................29

Mirror Write Consistency Cache......................................................................................29

Disk Spanning..............................................................................................................30

Number of Volume Groups.............................................................................................30

Contents 3