vt1211: Add documentation

[linux-2.6-microblaze.git] / Documentation / md.txt

diff --git a/Documentation/md.txt b/Documentation/md.txt
index df0b455..0668f9d 100644 (file)
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -200,6 +200,17 @@ All md devices contain:
      This can be written only while the array is being assembled, not
      after it is started.
 
+  layout
+     The "layout" for the array for the particular level.  This is
+     simply a number that is interpretted differently by different
+     levels.  It can be written while assembling an array.
+
+  resync_start
+     The point at which resync should start.  If no resync is needed,
+     this will be a very large number.  At array creation it will
+     default to 0, though starting the array as 'clean' will
+     set it much larger.
+
    new_dev
      This file can be written but not read.  The value written should
      be a block device number as major:minor.  e.g. 8:0
@@ -298,10 +309,18 @@ Each directory contains:
              faulty   - device has been kicked from active use due to
                          a detected fault
              in_sync  - device is a fully in-sync member of the array
+             writemostly - device will only be subject to read
+                        requests if there are no other options.
+                        This applies only to raid1 arrays.
              spare    - device is working, but not a full member.
                         This includes spares that are in the process
                         of being recoverred to
        This list make grow in future.
+       This can be written to.
+       Writing "faulty"  simulates a failure on the device.
+       Writing "remove" removes the device from the array.
+       Writing "writemostly" sets the writemostly flag.
+       Writing "-writemostly" clears the writemostly flag.
 
       errors
        An approximate count of read errors that have been detected on