HP-UX System Administrator's Guide: Logical Volume Management (762803-001, March 2014)
2.4.2 Internal Performance Factors.......................................................................................32
2.4.2.1 Scheduling Policy...............................................................................................32
2.4.2.2 Mirror Write Consistency Cache..........................................................................32
2.4.2.3 Disk Spanning...................................................................................................33
2.4.2.4 Number of Volume Groups.................................................................................33
2.4.2.5 Physical Volume Groups.....................................................................................33
2.4.2.6 Snapshots and Performance................................................................................33
2.4.3 Increasing Performance Through Disk Striping...............................................................34
2.4.3.1 Determining Optimum Stripe Size.........................................................................35
2.4.3.2 Interactions Between Mirroring and Striping..........................................................36
2.4.4 Increasing Performance Through I/O Channel Separation..............................................36
2.5 Configuring LVM I/O Timeout Parameters............................................................................36
2.6 Planning for Recovery........................................................................................................37
2.6.1 Preparing for LVM System Recovery..............................................................................38
2.6.1.1 Example Script for LVM Configuration Recording.....................................................40
3 Administering LVM....................................................................................41
3.1 Administration Tools..........................................................................................................41
3.2 Displaying LVM Information................................................................................................44
3.2.1 Information on Volume Groups....................................................................................44
3.2.2 Information on Physical Volumes..................................................................................45
3.2.3 Information on Logical Volumes...................................................................................45
3.3 Common LVM Tasks..........................................................................................................46
3.3.1 Initializing a Disk for LVM Use.....................................................................................46
3.3.2 Creating a Volume Group..........................................................................................47
3.3.2.1 Creating the Volume Group Device File.................................................................47
3.3.2.2 Creating a Version 1.0 Volume Group..................................................................48
3.3.2.3 Creating a Version 2.x Volume Group..................................................................48
3.3.3 Migrating a Volume Group to a Different Version: vgversion............................................49
3.3.3.1 Determining the Version of a Volume Group...........................................................49
3.3.3.2 Command Syntax..............................................................................................50
3.3.3.3 Review Mode: vgversion -r..................................................................................50
3.3.3.4 Example of Migrating a Volume Group to a Different Version..................................51
3.3.3.5 Migration Recovery............................................................................................53
3.3.3.5.1 Example Recovery......................................................................................53
3.3.4 Adding a Disk to a Volume Group...............................................................................54
3.3.5 Removing a Disk from a Volume Group........................................................................54
3.3.6 Creating a Logical Volume.........................................................................................55
3.3.6.1 Creating a Striped Logical Volume.......................................................................55
3.3.6.2 Creating a Mirrored Logical Volume.....................................................................55
3.3.7 Extending a Logical Volume........................................................................................56
3.3.7.1 Extending a Logical Volume to a Specific Disk........................................................57
3.3.8 Reducing a Logical Volume.........................................................................................57
3.3.9 Adding a Mirror to a Logical Volume...........................................................................58
3.3.10 Removing a Mirror from a Logical Volume...................................................................59
3.3.11 Renaming a Logical Volume.......................................................................................59
3.3.12 Removing a Logical Volume.......................................................................................60
3.3.13 Exporting a Volume Group........................................................................................60
3.3.14 Importing a Volume Group........................................................................................61
3.3.15 Modifying volume group parameters...........................................................................61
3.3.15.1 vgmodify for a Version 1.0 Volume Group............................................................62
3.3.15.2 Example: vgmodify for a Version 1.0 Volume Group..............................................62
3.3.15.3 vgmodify for a Version 2.x Volume Group............................................................65
3.3.15.4 Example: vgmodify for a Version 2.x Volume Group..............................................66
4 Contents