diff --git a/templates/host-preseed.j2 b/templates/host-preseed.j2
index 9dca9a4..3fd66e2 100644
--- a/templates/host-preseed.j2
+++ b/templates/host-preseed.j2
@@ -11,13 +11,17 @@
 ### General definitions/overrides
 ###
 
+{% if debrelease is defined and debrelease %}
 # The Debian release to use (overrides the default)
 #debrelease="buster"
 debrelease="{debrelease}"
+{% endif %}
 
+{% if debmirror is defined and debmirror %}
 # The Debian mirror to use (overrides the default)
 #debmirror="http://debian.mirror.rafal.ca/debian"
 debmirror="{debmirror}"
+{% endif %}
 
 {% if addpkglist is defined and addpkglist %}
 # Additional packages (comma-separated) to install in the base system
@@ -25,6 +29,12 @@ debmirror="{debmirror}"
 addpkglist="{addpkglist}"
 {% endif %}
 
+{% if filesystem is defined and filesystem %}
+# Alternate filesystem for system volumes (/, /var/lib/ceph, /var/lib/zookeeper)
+#filesystem=ext4
+filesystem="{filesystem}"
+{% endif %}
+
 {% if skip_blockcheck is defined and skip_blockcheck %}
 # Skip block zeroing; only recommended for testing, slow, low-endurance, or known-zeroed block devices.
 skip_blockcheck="y"
diff --git a/templates/install.sh b/templates/install.sh
index ef80190..cf477e3 100755
--- a/templates/install.sh
+++ b/templates/install.sh
@@ -133,9 +133,24 @@ seed_config() {
     # Fetch the seed config
     tftp -m binary "${seed_host}" -c get "${seed_file}" /tmp/install.seed
 
+    # Load the variables from the seed config
     . /tmp/install.seed || exit 1
 
-    if [[ -n "${addpkglist}" ]]; then
+    # Ensure optional configurations are set to defaults if unset
+    if [[ -z ${filesystem} ]]; then
+        filesystem="${default_filesystem}"
+    fi
+
+    if [[ -z ${debrelease} ]]; then
+        debrelease="${default_debrelease}"
+    fi
+
+    if [[ -z ${debmirror} ]]; then
+        debmirror="${default_debmirror}"
+    fi
+
+    # Append the addpkglist to the suppkglist if present
+    if [[ -n ${addpkglist} ]]; then
         suppkglist="${suppkglist},${addpkglist}"
     fi