From d2e5eacb7fed1fd6d51254396f6e636627d2617a Mon Sep 17 00:00:00 2001
From: Dale Fu <Dale.Fu@ibm.com>
Date: Mon, 22 Jun 2026 22:44:48 -0400
Subject: [PATCH] Sync VM filesystem before snapshot to prevent data loss

Signed-off-by: Dale Fu <Dale.Fu@ibm.com>
---
 scripts/lxd_vm.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/scripts/lxd_vm.sh b/scripts/lxd_vm.sh
index f2ca7be..adf6f63 100755
--- a/scripts/lxd_vm.sh
+++ b/scripts/lxd_vm.sh
@@ -447,6 +447,10 @@ build_image() {
       fi
   fi
 
+  # Flush VM filesystem cache to ensure all writes are persisted before snapshot
+  msg "Syncing VM filesystem to disk."
+  lxc exec "${BUILD_VM}" -- sync
+
   msg "Runner build complete."
 
   # Snapshotting (VM Level) ---