Has anybody had good luck using FAI where it repartitions on a system that previously contained an lvm setup?

Christoph Kluenter ck at iphh.net
Thu Jul 11 10:15:54 CEST 2013

Hi Ken,

* Am Wed, Jul 10 at 15:05:10 -0500 , schrieb Ken Hahn:
> Hello,
> I'm trying to get FAI working for an install of several labs using
> Debian Wheezy.  I'm using the latest wheezy install of FAI (which is
> version 4.0.6).
> My install process has worked fine when I empty out the disk (dd
> if=/dev/zero of=/dev/sda bs=1024 count=512 is my friend) of the client
> machine.  However, when I try to reinstall on top of a previous system
> which used LVM, I continually have failures.  This led me to a few
> questions specifically about setup-storage:
> 1. Is there any documentation on all the names for the pre and post
> dependencies for a command?  I'm having a very hard time deciding if
> there's a bug, or if my config has problems because it's hard for me to
> decode these strings. Specifically, what is self_cleared_* and why does
> it sometimes have a dev node suffix, and other times have a logical
> volume name?
> 2. Has anybody had luck with installing where an lvm setup previously
> existed?  I see that the wipefs command always depends on a vgchange -a
> n command, and I don't understand how that could work, as the vgchange
> removes the device node. With no device node, there's no device to wipe.
>  (Also, I see that for lvm, wipefs refers to a path like vg/fscache
> instead of /dev/vg/fscache.  I'm not sure how that would ever work, either.)
> One of the few things that I can think of is that the kernel causes
> different behavior as to the dev nodes appearance/disappearance. I am
> using a stock debian kernel instead of the grml one because the grml one
> was crashing randomly on my test machine (which is similar to my lab
> machines).
> I appreciate any relevant feedback.

I had the same problem and added a script-hook.
It just wipes all disks before trying to partition them.
This script was posted on this list before I think.


commit f00f42e0d8cefa4ab759534b647b9fb275245dc6
Author: Christoph <ck at iphh.net>
Date:   Wed Jun 19 11:41:57 2013 +0000

    work around debian bug # #693701
diff --git a/hooks/partition.WIPEDISKS b/hooks/partition.WIPEDISKS
new file mode 100644
index 0000000..7d2b46a
--- /dev/null
+++ b/hooks/partition.WIPEDISKS
@@ -0,0 +1,49 @@
+# hooks/partition.WIPEDISKS
+# author : W. Walkowiak, 2013-01-03
+# changed: 
+# Stop LVM an MD RAIDs if existing and wipe all disks with wipefs and dd
+# $Id: $
+error=0; trap 'error=$(($?>$error?$?:$error))' ERR # save maximum error code
+#--- functions
+# stop volume groups
+echo "Stopping VGs:"
+vgchange -an $vg
+# stop MD RAID arrays
+echo "Stopping and removing MD RAID arrays:"
+mdadm --detail --scan 
+for array in $(mdadm --detail --scan | cut -d ' ' -f 2 | xargs readlink -f )
+  parts=$(mdadm --detail  $array | grep '/dev/' | grep -oE "[^ :]+$")
+  mdadm --stop $array
+  [ -x $array ] && mdadm --remove $array
+  for part in $parts; do
+    echo "zeroing $part"
+    mdadm --zero-superblock $part
+  done 
+rm -f /etc/mdadm/mdadm.conf
+# wipe all disks with wipefs and dd
+if [ -n "$disklist" ]; then
+  echo "Wiping boot sector of disks: $disklist"
+  for disk in $disklist; do
+    wipefs -a /dev/$disk
+    dd if=/dev/zero of=/dev/$disk bs=512 count=1
+  done
+exit $error

> -Ken Hahn

Christoph Kluenter                   E-Mail: support at iphh.net
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