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

358 Creating and administering volume sets
Raw device node access to component volumes
vset_devinfo=on:read-only Raw device nodes in read-only mode.
vset_devinfo=on:read-write Raw device nodes in read-write mode.
This field is not displayed if
makedev is set to off.
Note: 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 as described in
“Controlling raw device access for an existing volume set” on page 358.
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.
Note: 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:
# vxvset [-g diskgroup] [-f] set \
compvol_access={read-only|read-write} vset
The compvol_access attribute can be specified to the vxvset set command to change
the access mode to 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 read-
only
.
The following example sets the
makedev=on and compvol_access=read-only
attributes on a volume set, myvset2, in the disk group, mydg:
# vxvset -g mydg set makedev=on myvset2
The next example sets the compvol_access=read-write attribute on the volume set,
myvset2:
# vxvset -g mydg set compvol_access=read-write myvset2
The final example removes raw device node access for the volume set, myvset2:
# vxvset -g mydg set makedev=off myvset2