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

The following example creates a volume set, myvset1, containing the volume,
myvol1, in the disk group, mydg, with raw device access enabled in read-write
mode:
# vxvset -g mydg -o makedev=on -o compvol_access=read-write \
make myvset1 myvol1
Displaying the raw device access settings for a volume set
You can use the vxprint -m command to display the current settings for a volume
set. If the makedev attribute is set to on, one of the following strings is displayed
in the output:
Raw device nodes in read-only mode.vset_devinfo=on:read-only
Raw device nodes in read-write mode.vset_devinfo=on:read-write
A string is not displayed if makedev is set to off.
If the output from the vxprint -m command is fed to the vxmake command to
recreate a volume set, the vset_devinfo attribute must set to off. Use the vxvset
set command to re-enable raw device access with the desired access mode.
See “Controlling raw device access for an existing volume set” on page 391.
Controlling raw device access for an existing volume set
To enable or disable raw device node access for an existing volume set, use the
following command:
# vxvset [-g diskgroup] [-f] set makedev={on|off} vset
The makedev attribute can be specified to the vxvset set command to create
(makedev=on) or remove (makedev=off) the raw device nodes for the component
volumes of a volume set. If any of the component volumes are open, the -f (force)
option must be specified to set the attribute to off.
Specifying makedev=off removes the existing raw device nodes from the
/dev/vx/rdsk/diskgroup directory.
If the makedev attribute is set to off, and you use the mknod command to create
the raw device nodes, you cannot read from or write to those nodes unless you
set the value of makedev to on.
The syntax for setting the compvol_access attribute on a volume set is:
391Creating and administering volume sets
Raw device node access to component volumes