VERITAS Volume Manager 3.1 Administrator's Guide

Introduction to Volume Manager
Virtual Object Data Organization (Volume Layouts)
Chapter 1 39
Figure 1-8 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.
For an example of a volume in a concatenated configuration, see Figure
1-9, Example of a Volume in a Concatenated Configuration,
Figure 1-9 Example of a Volume in a Concatenated Configuration
In the example shown in Figure 1-10, Example of Spanning,, the first six
blocks of data (B1 through B6) use most of the space on the disk that VM
disk disk01 is assigned to. This requires space only on subdisk
disk01-01 on VM disk disk01. However, the last two blocks of data, B7
and B8, use only a portion of the space on the disk that VM disk disk02
is assigned to.
The remaining free space on VM disk disk02 can be put to other uses. In
VM Disk
Physical Disk
Plex
B = Block of data
devname
disk01
disk01-01
disk01-01
B1
B2
B3
B4
VM Disk
Physical Disk
Subdisks
disk01-02
disk01-03
disk01-01
disk01-03
disk01-02
disk01-01
Concatenated
devname
disk01
disk01-03
Volume
vol01-01
vol01
Plex
disk01-01
disk01-02
vol01-01
disk01-03
disk01-01
disk01-02