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

232 Creating volumes
Using vxassist
vxassist obtains most of the information it needs from sources other than your input.
vxassist obtains information about the existing objects and their layouts from the
objects themselves.
For tasks requiring new disk space,
vxassist seeks out available disk space and allocates
it in the configuration that conforms to the layout specifications and that offers the best use
of free space.
The
vxassist command takes this form:
# vxassist [options] keyword volume [attributes...]
where keyword selects the task to perform. The first argument after a vxassist
keyword, volume, is a volume name, which is followed by a set of desired volume
attributes. For example, the keyword
make allows you to create a new volume:
# vxassist [options] make volume length [attributes]
The length of the volume can be specified in sectors, kilobytes, megabytes, or gigabytes
using a suffix character of
s, k, m, or g. If no suffix is specified, the size is assumed to be
in sectors. See the vxintro(1M) manual page for more information on specifying units.
Additional attributes can be specified as appropriate, depending on the characteristics that
you wish the volume to have. Examples are stripe unit width, number of columns in a
RAID-5 or stripe volume, number of mirrors, number of logs, and log type.
Note: By default, the vxassist command creates volumes in a default disk group
according to the rules given in “Rules for determining the default disk group” on
page 160. To use a different disk group, specify the -g diskgroup option to vxassist.
For details of available
vxassist keywords and attributes, refer to the vxassist(1M)
manual page.
The section, “Creating a volume on any disk” on page 234 describes the simplest way to
create a volume with default attributes. Later sections describe how to create volumes with
specific attributes. For example, “Creating a volume on specific disks” on page 235
describes how to control how
vxassist uses the available storage space.
Setting default values for vxassist
The default values that the vxassist command uses may be specified in the file /etc/
default/vxassist. The defaults listed in this file take effect if you do not override
them on the command line, or in an alternate defaults file that you specify using the
-d
option. A default value specified on the command line always takes precedence.
vxassist also has a set of built-in defaults that it uses if it cannot find a value defined
elsewhere.
Note: You must create the /etc/default directory and the vxassist default file if
these do not already exist on your system.