diff --git a/packaging/DEBIAN-multipath/multipath.conf.example b/packaging/DEBIAN-multipath/multipath.conf.example
index 320131d..95fa788 100644
--- a/packaging/DEBIAN-multipath/multipath.conf.example
+++ b/packaging/DEBIAN-multipath/multipath.conf.example
@@ -1,12 +1,19 @@
-# /etc/multipath.conf — installed by truenas-proxmox-multipath
-# This file is only created if /etc/multipath.conf does not already exist.
-# If you have an existing multipath.conf, merge the 'devices' section below
-# into it manually.
+# /etc/multipath.conf — reference for truenas-proxmox-multipath
+#
+# postinst installs this automatically if /etc/multipath.conf does not exist.
+# If you already have a multipath.conf, postinst appends the tagged block below
+# instead of overwriting your file.
+#
+# The BEGIN/END markers let postinst update the stanza on upgrade and postrm
+# strip it on remove without touching the rest of your config.
 
 defaults {
     find_multipaths  yes
 }
 
+# BEGIN truenas-proxmox-multipath
+# Managed by truenas-proxmox-multipath. Do not edit between these markers.
+# To customise, remove the package tags and maintain the block yourself.
 devices {
     device {
         vendor                "TrueNAS"
@@ -18,3 +25,4 @@ devices {
         no_path_retry         5
     }
 }
+# END truenas-proxmox-multipath
diff --git a/packaging/DEBIAN-multipath/postinst b/packaging/DEBIAN-multipath/postinst
index ea8c35b..14ecb5a 100644
--- a/packaging/DEBIAN-multipath/postinst
+++ b/packaging/DEBIAN-multipath/postinst
@@ -17,17 +17,48 @@ install_plugin() {
     cp "${INSTALL_DIR}/TrueNASMultipath.pm" "$PLUGIN_DST"
 }
 
+BLOCK_BEGIN="# BEGIN truenas-proxmox-multipath"
+BLOCK_END="# END truenas-proxmox-multipath"
+
+# Appends or replaces the tagged TrueNAS device stanza in multipath.conf.
+# Safe to call on upgrade — idempotent via BEGIN/END markers.
 install_multipath_conf() {
-    if [ -f "$MULTIPATH_CONF" ]; then
-        log "${MULTIPATH_CONF} already exists — not overwriting"
-        log "Ensure it contains a 'devices' section for TrueNAS iSCSI Disk"
-        log "See ${INSTALL_DIR}/multipath.conf.example for reference"
-        return 0
+    local stanza
+    stanza=$(cat <<STANZA
+${BLOCK_BEGIN}
+# Managed by truenas-proxmox-multipath. Do not edit between these markers.
+# To customise, remove the package tags and maintain the block yourself.
+devices {
+    device {
+        vendor                "TrueNAS"
+        product               "iSCSI Disk"
+        path_grouping_policy  multibus
+        path_checker          tur
+        failback              immediate
+        rr_weight             uniform
+        no_path_retry         5
+    }
+}
+${BLOCK_END}
+STANZA
+)
+
+    if [ ! -f "$MULTIPATH_CONF" ]; then
+        log "Creating ${MULTIPATH_CONF} with defaults + TrueNAS device stanza"
+        printf 'defaults {\n    find_multipaths  yes\n}\n\n%s\n' "$stanza" > "$MULTIPATH_CONF"
+    elif grep -qF "$BLOCK_BEGIN" "$MULTIPATH_CONF"; then
+        log "Updating existing TrueNAS stanza in ${MULTIPATH_CONF}"
+        # Replace the block between markers (inclusive) with the new stanza
+        perl -i -0777 -pe \
+            "s|\Q${BLOCK_BEGIN}\E.*?\Q${BLOCK_END}\E|${stanza}|s" \
+            "$MULTIPATH_CONF"
+    else
+        log "Appending TrueNAS device stanza to existing ${MULTIPATH_CONF}"
+        printf '\n%s\n' "$stanza" >> "$MULTIPATH_CONF"
     fi
-    log "Installing ${MULTIPATH_CONF}"
-    cp "${INSTALL_DIR}/multipath.conf.example" "$MULTIPATH_CONF"
+
     systemctl enable multipathd 2>/dev/null || true
-    systemctl start multipathd  2>/dev/null || true
+    systemctl start  multipathd 2>/dev/null || true
     log "multipathd enabled and started"
 }
 
diff --git a/packaging/DEBIAN-multipath/postrm b/packaging/DEBIAN-multipath/postrm
index ea065b1..564e08d 100644
--- a/packaging/DEBIAN-multipath/postrm
+++ b/packaging/DEBIAN-multipath/postrm
@@ -3,6 +3,9 @@
 set -e
 
 PLUGIN_DST="/usr/share/perl5/PVE/Storage/Custom/TrueNASMultipath.pm"
+MULTIPATH_CONF="/etc/multipath.conf"
+BLOCK_BEGIN="# BEGIN truenas-proxmox-multipath"
+BLOCK_END="# END truenas-proxmox-multipath"
 LOG_FILE="/var/log/truenas-proxmox-install.log"
 
 log() {
@@ -16,9 +19,16 @@ case "$1" in
             rm -f "$PLUGIN_DST"
         fi
 
+        if [ -f "$MULTIPATH_CONF" ] && grep -qF "$BLOCK_BEGIN" "$MULTIPATH_CONF"; then
+            log "Removing TrueNAS stanza from ${MULTIPATH_CONF}"
+            perl -i -0777 -pe \
+                "s|\n?\Q${BLOCK_BEGIN}\E.*?\Q${BLOCK_END}\E\n?||s" \
+                "$MULTIPATH_CONF"
+        fi
+
         log "Restarting Proxmox VE services ..."
-        pvedaemon restart 2>/dev/null && log "pvedaemon restarted" || true
-        pveproxy restart  2>/dev/null && log "pveproxy restarted"  || true
+        if pvedaemon restart 2>/dev/null; then log "pvedaemon restarted"; fi
+        if pveproxy  restart 2>/dev/null; then log "pveproxy restarted";  fi
         log "Done."
         ;;
     upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)