Grow: report better message when --grow --chunk cannot work.

[thirdparty/mdadm.git] / mdmon.8

diff --git a/mdmon.8 b/mdmon.8
index 8a482b34070af03e3677c6e0afe4b472a8e353aa..a968cdb031aa8e9e9b2f1f45a710e292eb835b87 100644 (file)
--- a/mdmon.8
+++ b/mdmon.8
@@ -1,11 +1,11 @@
 .\" See file COPYING in distribution for details.
 .\" See file COPYING in distribution for details.

-.TH MDMON 8 "" v3.1.1
+.TH MDMON 8 "" v3.2.5

 .SH NAME
 mdmon \- monitor MD external metadata arrays
 
 .SH SYNOPSIS
 
 .SH NAME
 mdmon \- monitor MD external metadata arrays
 
 .SH SYNOPSIS
 

-.BI mdmon " [--all] [--takeover] CONTAINER"
+.BI mdmon " [--all] [--takeover] [--foreground] CONTAINER"

 
 .SH OVERVIEW
 The 2.6.27 kernel brings the ability to support external metadata arrays.
 
 .SH OVERVIEW
 The 2.6.27 kernel brings the ability to support external metadata arrays.


@@ -104,7 +104,7 @@ within those disks.  MD metadata in comparison defines a 1:1
 relationship between a set of block devices and a raid array.  For
 example to create 2 arrays at different raid levels on a single
 set of disks, MD metadata requires the disks be partitioned and then
 relationship between a set of block devices and a raid array.  For
 example to create 2 arrays at different raid levels on a single
 set of disks, MD metadata requires the disks be partitioned and then

-each array can created be created with a subset of those partitions.  The
+each array can be created with a subset of those partitions.  The

 supported external formats perform this disk carving internally.
 .P
 Container devices simply hold references to all member disks and allow
 supported external formats perform this disk carving internally.
 .P
 Container devices simply hold references to all member disks and allow


@@ -131,6 +131,14 @@ The
 device to monitor.  It can be a full path like /dev/md/container, or a
 simple md device name like md127.
 .TP
 device to monitor.  It can be a full path like /dev/md/container, or a
 simple md device name like md127.
 .TP

+.B \-\-foreground
+Normally,
+.I mdmon
+will fork and continue in the background.  Adding this option will
+skip that step and run
+.I mdmon
+in the foreground.
+.TP

 .B \-\-takeover
 This instructs
 .I mdmon
 .B \-\-takeover
 This instructs
 .I mdmon


@@ -165,6 +173,7 @@ argument is over-written with the name of the container.  To allow for
 containers with names longer than 5 characters, this argument can be
 arbitrarily extended, e.g. to
 .BR \-\-all-active-arrays .
 containers with names longer than 5 characters, this argument can be
 arbitrarily extended, e.g. to
 .BR \-\-all-active-arrays .

+.TP

 
 .PP
 Note that
 
 .PP
 Note that


@@ -172,7 +181,7 @@ Note that
 is automatically started by
 .I mdadm
 when needed and so does not need to be considered when working with
 is automatically started by
 .I mdadm
 when needed and so does not need to be considered when working with

-RAID arrays.  The only times it is run other that by
+RAID arrays.  The only times it is run other than by

 .I  mdadm
 is when the boot scripts need to restart it after mounting the new
 root filesystem.
 .I  mdadm
 is when the boot scripts need to restart it after mounting the new
 root filesystem.


@@ -186,6 +195,11 @@ mounted there are special considerations when the root filesystem is
 mounted from an
 .I mdmon
 monitored device.
 mounted from an
 .I mdmon
 monitored device.

+Note that in general
+.I mdmon
+is needed even if the filesystem is mounted read-only as some
+filesystems can still write to the device in those circumstances, for
+example to replay a journal after an unclean shutdown.

 
 When the array is assembled by the
 .B initramfs
 
 When the array is assembled by the
 .B initramfs


@@ -195,23 +209,20 @@ as required.  This means that
 .I mdmon
 must be installed on the
 .B initramfs
 .I mdmon
 must be installed on the
 .B initramfs

-and there must be a writable filesystem (typically tmpfs) which
+and there must be a writable filesystem (typically tmpfs) in which

 .B mdmon
 can create a
 .B .pid
 and
 .B .sock
 .B mdmon
 can create a
 .B .pid
 and
 .B .sock

-file on.  The particular filesystem to use is given to mdmon at compile
+file.  The particular filesystem to use is given to mdmon at compile

 time and defaults to
 time and defaults to

-.BR /lib/init/rw .
+.BR /run/mdadm .

 
 

-This filesystem must persist through to the end of the boot sequence.
+This filesystem must persist through to shutdown time.

 
 After the final root filesystem has be instantiated (usually with
 .BR pivot_root )
 
 After the final root filesystem has be instantiated (usually with
 .BR pivot_root )

-and after
-.B /var
-is mounted writable,

 .I mdmon
 should be run with
 .I "\-\-all \-\-takeover"
 .I mdmon
 should be run with
 .I "\-\-all \-\-takeover"


@@ -219,20 +230,17 @@ so that the
 .I mdmon
 running from the
 .B initramfs
 .I mdmon
 running from the
 .B initramfs

-can be replaced with one running in the main root.
+can be replaced with one running in the main root, and so the
+memory used by the initramfs can be released.

 
 At shutdown time,
 .I mdmon
 should not be killed along with other processes.  Also as it holds a
 file (socket actually) open in
 
 At shutdown time,
 .I mdmon
 should not be killed along with other processes.  Also as it holds a
 file (socket actually) open in

-.B /var
-it will not be possible to unmount
-.B /var
-if it is a separate filesystem.  Rather the
-.B /var
-filesystem, like the root filesystem, should be remounted read-only.
-
-
+.B /dev
+(by default) it will not be possible to unmount
+.B /dev
+if it is a separate filesystem.

 
 .SH EXAMPLES
 
 
 .SH EXAMPLES
 


@@ -241,9 +249,9 @@ filesystem, like the root filesystem, should be remounted read-only.
 Any
 .I mdmon
 which is currently running is killed and a new instance is started.
 Any
 .I mdmon
 which is currently running is killed and a new instance is started.

-This should be run late in the boot sequence and particularly after
-.B /var
-is mounted and writable.
+This should be run during in the boot sequence if an initramfs was
+used, so that any mdmon running from the initramfs will not hold
+the initramfs active.

 .SH SEE ALSO
 .IR mdadm (8),
 .IR md (4).
 .SH SEE ALSO
 .IR mdadm (8),
 .IR md (4).