add a little more detail to this page;

help/ok jsing

1 files changed, 11 insertions, 3 deletions

diff --git a/share/man/man4/diskmap.4 b/share/man/man4/diskmap.4
index bbe9f115c1c..75e85930b6b 100644
--- a/share/man/man4/diskmap.4
+++ b/share/man/man4/diskmap.4
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: diskmap.4,v 1.1 2010/08/19 15:45:35 jsing Exp $
+.\"     $OpenBSD: diskmap.4,v 1.2 2010/09/07 12:34:22 jmc Exp $
 .\"
 .\" Copyright (c) 2010 Joel Sing <jsing@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: August 19 2010 $
+.Dd $Mdocdate: September 7 2010 $
 .Dt DISKMAP 4
 .Os
 .Sh NAME
@@ -30,6 +30,14 @@ an actual device and open that device in one atomic operation.
 This is achieved via the DIOCMAP
 .Xr ioctl 2
 command.
+.Pp
+The ability to use a disklabel UID is helpful in situations
+where a disk may appear to the operating system under different device names.
+For example,
+plugging USB keys into differently configured systems (think sd0 or sd1),
+or swapping between IDE and AHCI on a disk controller (wd0 or sd0).
+Although the device names may change,
+the operating system is still able to identify the disk by its UID.
 .Sh FILES
 .Bl -tag -width /dev/diskmap -compact
 .It Pa /dev/diskmap
@@ -37,7 +45,7 @@ diskmap device
 .El
 .Sh SEE ALSO
 .Xr ioctl 2 ,
-.Xr MAKEDEV 8
+.Xr disklabel 8
 .Sh HISTORY
 The
 .Nm