Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 1, Understanding VERITAS Volume Manager
Volume Layouts in VxVM
19
Example of Concatenation
You can use concatenation with multiple subdisks when there is insufficient contiguous
space for the plex on any one disk. This form of concatenation can be used for load
balancing between disks, and for head movement optimization on a particular disk.
The figure, “Example of Spanning” on page 20, shows data spread over two subdisks in a
spanned plex. The blocks n, n+1, n+2 and n+3 (numbered relative to the start of the plex)
are contiguous on the plex, but actually come from two distinct subdisks from two distinct
physical disks.
disk01
VM Disk
Physical Disk
Plex with
Data Blocksn n+1 n+2 n+3
devname
disk01-01 disk01-03
disk01-01 disk01-03
Subdisks
nn+1 n+2 n+3
disk01-02
Data in
disk01-01
Data in
disk01-03
disk01-03disk01-01
Concatenated Subdisks