diff -Nru makedumpfile-1.6.8/debian/changelog makedumpfile-1.6.8/debian/changelog
--- makedumpfile-1.6.8/debian/changelog	2020-12-28 13:42:26.000000000 -0300
+++ makedumpfile-1.6.8/debian/changelog	2021-01-28 18:06:29.000000000 -0300
@@ -1,3 +1,9 @@
+makedumpfile (1:1.6.8-2ubuntu2) hirsute; urgency=low
+
+  * Bump crashkernel size for s390x. (LP: #1877533)
+
+ -- Thadeu Lima de Souza Cascardo <cascardo@canonical.com>  Thu, 28 Jan 2021 18:06:29 -0300
+
 makedumpfile (1:1.6.8-2ubuntu1) hirsute; urgency=low
 
   * Merge from Debian unstable. Remaining changes:
diff -Nru makedumpfile-1.6.8/debian/kdump-tools.postinst makedumpfile-1.6.8/debian/kdump-tools.postinst
--- makedumpfile-1.6.8/debian/kdump-tools.postinst	2020-12-27 12:44:02.000000000 -0300
+++ makedumpfile-1.6.8/debian/kdump-tools.postinst	2021-01-28 18:01:59.000000000 -0300
@@ -22,6 +22,41 @@
 	mv -f "$INITCONFFILE.$$" "$INITCONFFILE"
 }
 
+update_zipl() {
+
+	if [ ! -f /etc/zipl.conf ]; then
+		return;
+	fi
+
+	DI_PRESET="196M"
+	OLD_PRESET="384M-:128M"
+	DEF_PRESET="2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M"
+	HAS_CRASHKERNEL="$(grep crashkernel /etc/zipl.conf)" || true
+
+	if test -z "$HAS_CRASHKERNEL"; then
+		sed -i "s|^\s*parameters\s*=\s*\"\?|&crashkernel=${DEF_PRESET} |" /etc/zipl.conf
+	elif dpkg --compare-versions "$1" lt 1:1.6.7-4ubuntu2; then
+
+		# zipl-installer and some old upgrade paths for s390-tools will add crashkernel=196M.
+		# Overriding such a default value is preferrable than leaving the system unable to dump
+		# on default configurations.
+		# We should do that in both cases of a new install and an upgrade from an earlier version.
+		sed -i "s/crashkernel=${DI_PRESET}/crashkernel=${DEF_PRESET}/" /etc/zipl.conf
+
+		# If the user has set crashkernel before installing kdump-tools, we should
+	        # keep the users' value. Otherwise, if this is an upgrade from an older version,
+		# update the crashkernel default value.
+		if [ -n "$1" ]; then
+			sed -i "s/crashkernel=${OLD_PRESET}/crashkernel=${DEF_PRESET}/" /etc/zipl.conf
+		fi
+
+	fi
+
+	if [ -e /usr/sbin/zipl ]; then
+		/usr/sbin/zipl
+	fi
+}
+
 # summary of how this script can be called:
 #        * <postinst> `configure' <most-recently-configured-version>
 #        * <old-postinst> `abort-upgrade' <new version>
@@ -55,14 +90,9 @@
 
 	# Customize crashkernel= value according to architecture
 	ARCH="$(arch)"
-	DEF_PRESET="384M-:128M"
 	case "$ARCH" in
 		s390x)
-			HAS_CRASHKERNEL="$(grep crashkernel /etc/zipl.conf)" || true
-			if test -z "$HAS_CRASHKERNEL"; then
-				sed -i "s|^\s*parameters\s*=\s*\"\?|&crashkernel=${DEF_PRESET} |" /etc/zipl.conf
-				zipl
-			fi
+			update_zipl "$2"
 			CIO_IGNORE="$(cio_ignore -u -k)"
 			sed -i "s/\#KDUMP_CMDLINE_APPEND/KDUMP_CMDLINE_APPEND/" "$INITCONFFILE"
 			sed -i "/KDUMP_CMDLINE_APPEND/{s|\"$| ${CIO_IGNORE}\"|}" "$INITCONFFILE"