r215 - mdadm/trunk/debian

[madduck at users.alioth.debian.org]

Author: madduck
Date: 2006-10-10 16:38:37 +0000 (Tue, 10 Oct 2006)
New Revision: 215

Modified:
   mdadm/trunk/debian/FAQ
   mdadm/trunk/debian/README.recipes
   mdadm/trunk/debian/changelog
Log:
docs updates

Modified: mdadm/trunk/debian/FAQ
===================================================================
--- mdadm/trunk/debian/FAQ	2006-10-10 08:18:18 UTC (rev 214)
+++ mdadm/trunk/debian/FAQ	2006-10-10 16:38:37 UTC (rev 215)
@@ -229,8 +229,6 @@
   If you want/must used LVM or RAID0, put it on RAID1 arrays (RAID10/RAID1+0,
   or LVM on RAID1).
 
- -- martin f. krafft <madduck at debian.org>  Fri, 06 Oct 2006 15:39:58 +0200
-
 10. Can I cancel a running array check (checkarray)?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   See the -x option in the `checkarray --help` output.
@@ -257,4 +255,28 @@
         - DEVICE partitions
         + DEVICE /dev/hd[ab]* /dev/hdc[123]
 
+12. mdadm -E / mkconf report different arrays with the same device
+    name / minor number. What gives?
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  In almost all cases, mdadm updates the super-minor field in an array's
+  superblock when assembling the array. It does *not* do this for RAID0
+  arrays. Thus, you may end up seeing something like this when you run 
+  mdadm -E or mkconf:
+
+    ARRAY /dev/md0 level=raid0 num-devices=2 UUID=abcd...
+    ARRAY /dev/md0 level=raid1 num-devices=2 UUID=dcba...
+
+  Note how the two arrays have different UUIDs but both appear as /dev/md0.
+
+  The solution in this case is to explicitly tell mdadm to update the
+  superblock of the RAID0 array. Assuming that the RAID0 array in the above
+  example should really be /dev/md1:
+
+    mdadm --stop /dev/md1
+    mdadm --assemble --update=super-minor --uuid=abcd... /dev/md1
+
+  See also http://bugs.debian.org/386315 and recipe #12 in README.recipes .
+
+ -- martin f. krafft <madduck at debian.org>  Fri, 06 Oct 2006 15:39:58 +0200
+
 $Id$

Modified: mdadm/trunk/debian/README.recipes
===================================================================
--- mdadm/trunk/debian/README.recipes	2006-10-10 08:18:18 UTC (rev 214)
+++ mdadm/trunk/debian/README.recipes	2006-10-10 16:38:37 UTC (rev 215)
@@ -134,9 +134,12 @@
     # for example, to set the preferred minor to 4:
     mdadm --assemble /dev/md4 /dev/sd[abc]1
 
-    # if this does not work (you need a 2.6 kernel), try:
-    mdadm --assemble --update super-minor /dev/md4 /dev/sd[abc]1
+    # this only works on 2.6 kernels, and only for RAID levels of 1 and above.
+    # for other MD arrays, you need to specify --update explicitly:
+    mdadm --assemble --update=super-minor /dev/md4 /dev/sd[abc]1
 
+    # see also item 12 in the FAQ contained with the Debian package.
+
  -- martin f. krafft <madduck at debian.org>  Fri, 06 Oct 2006 15:39:58 +0200
 
 $Id$

Modified: mdadm/trunk/debian/changelog
===================================================================
--- mdadm/trunk/debian/changelog	2006-10-10 08:18:18 UTC (rev 214)
+++ mdadm/trunk/debian/changelog	2006-10-10 16:38:37 UTC (rev 215)
@@ -4,12 +4,16 @@
     - --examine now reports chunk size also for RAID6 and RAID10
     - fix endianness issues with v1 superblocks (closes: #385726) and bitmap
       metadata.
-    - improved the message when mdadm detects similar superblocks
+    - improved message when mdadm detects similar superblocks
       (closes: #385951).
+    - Documents that the automatic update of the super-minor field in the
+      superblock when using a 2.6 kernel only applies to RAID levels 1 and
+      higher. RAID0 array superblocks must be manually updated
+      (closes: #386315, #388172).
   * Removed patch previously used to fix #385951 because it's not adequate.
     See the bug log for reasons.
 
- -- martin f. krafft <madduck at debian.org>  Tue, 10 Oct 2006 08:38:50 +0200
+ -- martin f. krafft <madduck at debian.org>  Tue, 10 Oct 2006 18:26:11 +0200
 
 mdadm (2.5.3.git200608202239-8) unstable; urgency=low