Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

In order to allocate a volume on SSD devices from enclr3 enclosure, following
command should be used:
# vxassist -g mydg make myvol 1G enclr:enclr3 mediatype:ssd
The allocation fails, if the command is specified in one of the following two ways:
# vxassist -g mydg make myvol 1G enclr:enclr1 mediatype:hdd
In the above case, volume myvol cannot be created as there are no HDD devices
in enclr1 enclosure.
# vxassist -g mydg make myvol 1G enclr:enclr2 mediatype:ssd
In the above case, volume myvol cannot be created as there are no SSD devices
in enclr2 enclosure.
Specifying ordered allocation of storage to volumes
Ordered allocation gives you complete control of space allocation. It requires that
the number of disks that you specify to the vxassist command must match the
number of disks that are required to create a volume. The order in which you
specify the disks to vxassist is also significant.
If you specify the -o ordered option to vxassist when creating a volume, any
storage that you also specify is allocated in the following order:
■ Concatenate disks.
■ Form columns.
■ Form mirrors.
For example, the following command creates a mirrored-stripe volume with 3
columns and 2 mirrors on 6 disks in the disk group, mydg:
# vxassist -b -g mydg -o ordered make mirstrvol 10g \
layout=mirror-stripe ncol=3 mydg01 mydg02 mydg03 mydg04 mydg05 mydg06
This command places columns 1, 2 and 3 of the first mirror on disks mydg01,
mydg02 and mydg03 respectively, and columns 1, 2 and 3 of the second mirror on
disks mydg04, mydg05 and mydg06 respectively.
Figure 8-1 shows an example of using ordered allocation to create a mirrored-stripe
volume.
Creating volumes
Creating a volume on specific disks
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