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

251Creating volumes
Initializing and starting a volume
Note: The subdisk definition for plex, db-01, must be specified on a single line. It is
shown here split across two lines because of space constraints.
The first plex, db-01, is striped and has five subdisks on two physical disks, mydg03
and mydg04. The second plex, db-02, is the preferred plex in the mirror, and has one
subdisk, ramd1-01, on a volatile memory disk.
For detailed information about how to use vxmake, refer to the vxmake(1M) manual page.
After creating a volume using
vxmake, you must initialize it before it can be used. The
procedure is described in “Initializing and starting a volume created using vxmake” on
page 252.
Initializing and starting a volume
If you create a volume using the vxassist command, vxassist initializes and starts the
volume automatically unless you specify the attribute
init=none.
When creating a volume, you can make it immediately available for use by specifying the
-b option to the vxassist command, as shown here:
# vxassist -b [-g diskgroup] make volume length layout=mirror
The -b option makes VxVM carry out any required initialization as a background task. It
also greatly speeds up the creation of striped volumes by initializing the columns in
parallel.
As an alternative to the
-b option, you can specify the init=active attribute to make a
new volume immediately available for use. In this example,
init=active is specified to
prevent VxVM from synchronizing the empty data plexes of a new mirrored volume:
# vxassist [-g diskgroup] make volume length layout=mirror \
init=active
Caution: There is a very small risk of errors occurring when the init=active attribute is
used. Although written blocks are guaranteed to be consistent, read errors can arise in the
unlikely event that
fsck attempts to verify uninitialized space in the file system, or if a file
remains uninitialized following a system crash. If in doubt, use the
-b option to vxassist
instead.
This command writes zeroes to the entire length of the volume and to any log plexes. It
then makes the volume active. You can also zero out a volume by specifying the attribute
init=zero to vxassist, as shown in this example:
# vxassist [-g diskgroup] make volume length layout=raid5 \
init=zero
Note: You cannot use the -b option to make this operation a background task.