.\" the Free Software Foundation; either version 2 of the License, or
.\" (at your option) any later version.
.\" See file COPYING in distribution for details.
-.TH MDADM 8 "" v3.2.3
+.TH MDADM 8 "" v3.2.5
.SH NAME
mdadm \- manage MD devices
.I aka
by a digit string). See below under
.BR "Auto Assembly" .
+.TP
+.B \-\-prefer=
+When
+.I mdadm
+needs to print the name for a device it normally finds the name in
+.B /dev
+which refers to the device and is shortest. When a path component is
+given with
+.B \-\-prefer
+.I mdadm
+will prefer a longer name if it contains that component. For example
+.B \-\-prefer=by-uuid
+will prefer a name in a subdirectory of
+.B /dev
+called
+.BR by-uuid .
+
+This functionality is currently only provided by
+.B \-\-detail
+and
+.BR \-\-monitor .
+
.SH For create, build, or grow:
.TP
.I mdadm
will not try to be so clever.
+.TP
+.BR \-o ", " \-\-readonly
+Start the array
+.B read only
+rather than read-write as normal. No writes will be allowed to the
+array, and no resync, recovery, or reshape will be started.
+
.TP
.BR \-a ", " "\-\-auto{=yes,md,mdp,part,p}{NN}"
Instruct mdadm how to create the device file if needed, possibly allocating
.BR \-a ", " \-\-add
hot-add listed devices.
If a device appears to have recently been part of the array
-(possibly it failed or was removed) the device is re\-added as describe
+(possibly it failed or was removed) the device is re\-added as described
in the next point.
If that fails or the device was never part of the array, the device is
added as a hot-spare.
.TP
.BR \-\-rebuild\-map ", " \-r
Rebuild the map file
-.RB ( /var/run/mdadm/map )
+.RB ( {MAP_PATH} )
that
.I mdadm
uses to help track which arrays are currently being assembled.
but leaves that to
.IR udev .
It does record information in
-.B /var/run/mdadm/map
+.B {MAP_PATH}
which will allow
.I udev
to choose the correct name.
.PP
.I mdadm
keeps a list of arrays that it has partially assembled in
-.B /var/run/mdadm/map
-(or
-.B /var/run/mdadm.map
-if the directory doesn't exist. Or maybe even
-.BR /dev/.mdadm.map ).
+.BR {MAP_PATH} .
If no array exists which matches
the metadata on the new device,
.I mdadm
.B /dev/md0
out of all such devices with a RAID superblock with a minor number of 0.
-.B " mdadm \-\-monitor \-\-scan \-\-daemonise > /var/run/mdadm"
+.B " mdadm \-\-monitor \-\-scan \-\-daemonise > /run/mdadm/mon.pid"
.br
If config file contains a mail address or alert program, run mdadm in
the background in monitor mode monitoring all md devices. Also write
pid of mdadm daemon to
-.BR /var/run/mdadm .
+.BR /run/mdadm/mon.pid .
.B " mdadm \-Iq /dev/somedevice"
.br
.BR mdadm.conf (5)
for more details.
-.SS /var/run/mdadm/map
+.SS {MAP_PATH}
When
.B \-\-incremental
mode is used, this file gets a list of arrays currently being created.
-If
-.B /var/run/mdadm
-does not exist as a directory, then
-.B /var/run/mdadm.map
-is used instead. If
-.B /var/run
-is not available (as may be the case during early boot),
-.B /dev/.mdadm.map
-is used on the basis that
-.B /dev
-is usually available very early in boot.
.SH DEVICE NAMES