diff --git a/include/persistent_data.hpp b/include/persistent_data.hpp
index 1c463b1d87..cdf7fd3e13 100644
--- a/include/persistent_data.hpp
+++ b/include/persistent_data.hpp
@@ -14,6 +14,8 @@
 #include <boost/beast/http/fields.hpp>
 #include <nlohmann/json.hpp>
 
+#include <unistd.h>
+
 #include <chrono>
 #include <cstdint>
 #include <filesystem>
@@ -359,7 +361,17 @@ class ConfigFile
         if (ec)
         {
             BMCWEB_LOG_ERROR("Failed to write file {}", ec.message());
+            return;
+        }
+
+        // Ensure session data reaches durable storage before BMC reboot can
+        // tear down the process or reset the platform.
+        if (::fsync(persistentFile.native_handle()) != 0)
+        {
+            BMCWEB_LOG_ERROR("Failed to fsync persistent data");
+            return;
         }
+        SessionStore::getInstance().clearNeedWrite();
     }
 
     std::string systemUuid;
diff --git a/include/sessions.hpp b/include/sessions.hpp
index 22aa3adf0c..1d94afb84e 100644
--- a/include/sessions.hpp
+++ b/include/sessions.hpp
@@ -434,6 +434,12 @@ class SessionStore
     {
         return needWrite;
     }
+
+    void clearNeedWrite()
+    {
+        needWrite = false;
+    }
+
     int64_t getTimeoutInSeconds() const
     {
         return std::chrono::seconds(timeoutInSeconds).count();
diff --git a/redfish-core/lib/managers.hpp b/redfish-core/lib/managers.hpp
index 2f67a4193b..69a04efbed 100644
--- a/redfish-core/lib/managers.hpp
+++ b/redfish-core/lib/managers.hpp
@@ -74,6 +74,15 @@ inline std::string getBMCUpdateServicePath()
     return "/xyz/openbmc_project/software";
 }
 
+inline void flushPersistentSessions()
+{
+    persistent_data::SessionStore::getInstance().applySessionTimeouts();
+    if (persistent_data::SessionStore::getInstance().needsWrite())
+    {
+        persistent_data::getConfig().writeData();
+    }
+}
+
 /**
  * Function reboots the BMC.
  *
@@ -82,6 +91,9 @@ inline std::string getBMCUpdateServicePath()
 inline void doBMCGracefulRestart(
     const std::shared_ptr<bmcweb::AsyncResp>& asyncResp)
 {
+    // Persist sessions before reboot so web UI login survives BMC reset.
+    flushPersistentSessions();
+
     const char* processName = "xyz.openbmc_project.State.BMC";
     const char* objectPath = "/xyz/openbmc_project/state/bmc0";
     const char* interfaceName = "xyz.openbmc_project.State.BMC";
@@ -109,6 +121,8 @@ inline void doBMCGracefulRestart(
 inline void doBMCForceRestart(
     const std::shared_ptr<bmcweb::AsyncResp>& asyncResp)
 {
+    flushPersistentSessions();
+
     const char* processName = "xyz.openbmc_project.State.BMC";
     const char* objectPath = "/xyz/openbmc_project/state/bmc0";
     const char* interfaceName = "xyz.openbmc_project.State.BMC";