Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

Technical Support ............................................................................................... 4
Chapter 1 Understanding Veritas Volume Manager ....................... 21
About Veritas Volume Manager ...................................................... 21
VxVM and the operating system ..................................................... 22
How data is stored .................................................................. 23
How VxVM handles storage management ......................................... 23
Physical objects ..................................................................... 23
Virtual objects ....................................................................... 29
Volume layouts in VxVM ............................................................... 36
Non-layered volumes .............................................................. 37
Layered volumes .................................................................... 37
Layout methods ..................................................................... 37
Concatenation, spanning, and carving ........................................ 38
Striping (RAID-0) ................................................................... 40
Mirroring (RAID-1) ................................................................. 44
Striping plus mirroring (mirrored-stripe or RAID-0+1) .................. 45
Mirroring plus striping (striped-mirror, RAID-1+0 or
RAID-10) ........................................................................ 46
RAID-5 (striping with parity) .................................................... 47
Online relayout ............................................................................ 54
How online relayout works ...................................................... 54
Limitations of online relayout .................................................. 57
Transformation characteristics ................................................ 58
Transformations and volume length .......................................... 58
Volume resynchronization ............................................................. 59
Dirty flags ............................................................................ 59
Resynchronization process ...................................................... 59
Dirty region logging ..................................................................... 60
Log subdisks and plexes .......................................................... 60
Sequential DRL ...................................................................... 61
SmartSync recovery accelerator ............................................... 61
Volume snapshots ........................................................................ 63
Comparison of snapshot features .............................................. 64
FastResync ................................................................................. 65
FastResync enhancements ....................................................... 66
Contents