Added gentoo-backup.sh script for making stage4 backups

gentoo-backup.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+bhost="$(hostname -s)"
+bdate="$(date +"%Y%m%d")"
+
+if [[ ! -d "/var/backup" ]]; then
+    mkdir /var/backup
+fi
+
+pushd /var/backup &>/dev/null || exit 2
+
+mkstage4 -s -l -q -C zst \
+    -e "/var/lib/containers/*" \
+    -e "/var/lib/machines/*" \
+    -e "/var/lib/portables/*" \
+    -e "/var/lib/libvirt/*" \
+    -e "/var/cache/binpkgs/*" \
+    -e "/home/*/*" \
+    "$bhost-stage4"
+
+popd &>/dev/null || exit 2