diff -Nru partman-multipath-4/commit.d/partition_multipath partman-multipath-4mpathsep1/commit.d/partition_multipath
--- partman-multipath-4/commit.d/partition_multipath	2011-01-19 03:03:36.000000000 -0200
+++ partman-multipath-4mpathsep1/commit.d/partition_multipath	2015-03-04 12:13:54.000000000 -0300
@@ -12,7 +12,14 @@
 	[ -f multipath ] || continue
 
 	# update partition mappings
-	kpartx -d -p -part $(cat device)
-	kpartx -a -p -part $(cat device)
+	# (use 'p' as multipath disk-partition separator because
+	#  parted_server/libparted creates the block devices and
+	#  lists multipath partitions with it for any components
+	#  of the installer; i.e., /dev/mapper/mpathXpY all over)
+	kpartx -d -p p $(cat device)
+	kpartx -a -p p $(cat device)
 done
 
+# exit code independent of for-loop
+exit 0
+
diff -Nru partman-multipath-4/debian/changelog partman-multipath-4mpathsep1/debian/changelog
--- partman-multipath-4/debian/changelog	2013-07-14 08:04:00.000000000 -0300
+++ partman-multipath-4mpathsep1/debian/changelog	2015-03-04 12:41:10.000000000 -0300
@@ -1,3 +1,20 @@
+partman-multipath (4mpathsep1) UNRELEASED; urgency=medium
+
+  * Multipath disk-partition separator overhaul (see #<p-m-bug>):
+
+    - commit.d/partition_multipath:
+      Use 'p' (not '-part') as multipath disk-partition separator.
+      (during d-i.)
+
+    - (new file) finish.d/fstab_hd_entries_multipath:
+      Use '-part' (not 'p') as multipath disk-partition separator.
+      (for the target.)
+
+      Use d-i number 41 in order to run it right after 'fstab_hd_entries'
+      (d-i number 40), which handles /dev/mapper/* (src:partman-target).
+
+ -- Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>  Wed, 04 Mar 2015 12:24:59 -0300
+
 partman-multipath (4) unstable; urgency=low
 
   [ Dmitrijs Ledkovs ]
diff -Nru partman-multipath-4/debian/di-numbers partman-multipath-4mpathsep1/debian/di-numbers
--- partman-multipath-4/debian/di-numbers	2011-01-19 03:03:36.000000000 -0200
+++ partman-multipath-4mpathsep1/debian/di-numbers	2015-03-04 12:15:41.000000000 -0300
@@ -1,2 +1,3 @@
 init.d lib/partman
 commit.d lib/partman
+finish.d lib/partman
diff -Nru partman-multipath-4/finish.d/fstab_hd_entries_multipath partman-multipath-4mpathsep1/finish.d/fstab_hd_entries_multipath
--- partman-multipath-4/finish.d/fstab_hd_entries_multipath	1969-12-31 21:00:00.000000000 -0300
+++ partman-multipath-4mpathsep1/finish.d/fstab_hd_entries_multipath	2015-03-04 12:30:11.000000000 -0300
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+[ -f /target/etc/fstab ] || exit 0
+
+# During d-i, the multipath disk-partition separator is 'p' (see commit.d/partition_multipath).
+# For the target, it's '-part' (see kpartx udev rules installed by src:multipath-tools).
+sed 's:^\(/dev/mapper/mpath[0-9]\+\)p:\1-part:' -i /target/etc/fstab
diff -Nru partman-multipath-4/finish.d/_numbers partman-multipath-4mpathsep1/finish.d/_numbers
--- partman-multipath-4/finish.d/_numbers	1969-12-31 21:00:00.000000000 -0300
+++ partman-multipath-4mpathsep1/finish.d/_numbers	2015-03-04 12:15:01.000000000 -0300
@@ -0,0 +1 @@
+41 fstab_hd_entries_multipath