Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

235Creating volumes
Creating a volume on specific disks
Note: To change the default layout, edit the definition of the layout attribute defined in
the /etc/default/vxassist file.
If there is not enough space on a single disk, vxassist creates a spanned volume. A
spanned volume is a concatenated volume with sections of disk space spread across more
than one disk. A spanned volume can be larger than any disk on a system, since it takes
space from more than one disk.
To create a concatenated, default volume, use the following form of the
vxassist
command:
# vxassist [-b] [-g diskgroup] make volume length
Note: Specify the -b option if you want to make the volume immediately available for
use. See “Initializing and starting a volume” on page 251 for details.
For example, to create the concatenated volume voldefault with a length of 10
gigabytes in the default disk group:
# vxassist -b make voldefault 10g
Creating a volume on specific disks
VxVM automatically selects the disks on which each volume resides, unless you specify
otherwise. If you want a volume to be created on specific disks, you must designate those
disks to VxVM. More than one disk can be specified.
To create a volume on a specific disk or disks, use the following command:
# vxassist [-b] [-g diskgroup] make volume length \
[layout=layout] diskname ...
For example, to create the volume volspec with length 5 gigabytes on disks mydg03
and mydg04, use the following command:
# vxassist -b -g mydg make volspec 5g mydg03 mydg04
The vxassist command allows you to specify storage attributes. These give you control
over the devices, including disks, controllers and targets, which
vxassist uses to
configure a volume. For example, you can specifically exclude disk mydg05:
# vxassist -b -g mydg make volspec 5g !mydg05
or exclude all disks that are on controller c2:
# vxassist -b -g mydg make volspec 5g !ctlr:c2
or include only disks on controller c1 except for target t5:
# vxassist -b -g mydg make volspec 5g ctlr:c1 !target:c1t5
If you want a volume to be created using only disks from a specific disk group, use the -g
option to
vxassist, for example:
# vxassist -g bigone -b make volmega 20g bigone10 bigone11
or alternatively, use the diskgroup attribute: