Virtualization and Sysprep Deployment Policies for SIMATIC PCS 7 Workstations

Siemens officially does not support using Microsoft Sysprep to clone or deploy workstations where SIMATIC PCS 7 and WinCC have already been installed. Changing the Windows computer name after WinCC installation corrupts the Microsoft SQL Server instance (MSSQL$WINCC), breaking internal server registrations (sys.servers) and Windows user security groups. For virtualized deployments (such as VMware vSphere environments with up to 40 VMs), Siemens mandates either utilizing SIMATIC Virtualization as a Service (SIVaaS) pre-validated virtual templates or deploying a clean, generalized Windows OS template via Sysprep, renaming the computer, and subsequently installing PCS 7 silently using the SIMATIC Management Console (SMMC).

Executive Summary

Modernization of industrial control systems increasingly involves consolidating physical workstations into virtual data centers utilizing VMware vSphere or Microsoft Hyper-V. When scaling virtual PCS 7 installations across dozens of Virtual Machines (such as 40 OS Clients and redundant server pairs), engineering teams seek rapid deployment methods, naturally turning to Microsoft System Preparation (Sysprep) or VM template cloning to replicate pre-built images. However, cloning pre-installed PCS 7 images introduces severe database corruption: Microsoft SQL Server retains the mother computer's NetBIOS name, local Windows user groups diverge, and WinCC Runtime fails to start. This technical guide details the technical root causes, outlines official Siemens policies, and establishes validated deployment workflows.

Virtualization in PCS 7: SIVaaS vs Custom VMware Architectures

Siemens addresses large-scale virtualization through two paths:

SIMATIC Virtualization as a Service (SIVaaS): A pre-engineered, turnkey virtualization solution comprising tested server hardware, configured ESXi hypervisors, and pre-packaged virtual machine templates managed under standardized lifecycle SLAs.
Customer-Managed Virtual Environments: Systems engineered on customer hardware conforming strictly to the Siemens Virtualization Guidelines (e.g. dedicated NIC passthrough, reserved RAM without overcommitment, and fixed disk provisioning).

Why Sysprep Breaks WinCC and Microsoft SQL Server

SIMATIC WinCC relies on an embedded instance of Microsoft SQL Server (MSSQL$WINCC). When WinCC is installed:

SQL Server permanently records the current Windows computer name into internal system metadata tables (sys.servers).
Windows security creates local user groups embedded with the host name (e.g. SQLServer2008MSSQLUser$<MotherPC>$WINCC).
When Sysprep generalizes the OS and generates a new computer name, SQL Server detects a hostname mismatch. Queries referencing @@SERVERNAME return the old mother name, causing WinCC database attachments to abort.

The Post-Install Computer Name Constraint (SIOS Entry 5708281)

Siemens FAQ Entry ID 5708281 establishes the foundational rule: 'You must never change the computer name after installing WinCC and after the first startup of the SQL Server'. If a name change occurs, the entire SQL Server instance and WinCC subsystems must be uninstalled and reinstalled from scratch.

Deployment Strategy and Virtualization Platform Comparison

The following table compares deployment methodologies for multi-node virtual PCS 7 installations:

Deployment StrategySysprep TimingCompliance with SiemensScalability & SpeedRisk ProfileCloning Pre-Installed PCS 7Post-PCS 7 InstallationUnsupported (Prohibited)Fast but fatalBroken SQL Server, invalid security groups.SIVaaS Master TemplatesSpecialized Siemens ScriptsOfficially CertifiedVery Fast (~15 min/VM)Zero risk (Pre-validated vendor automation).OS Template + SMMC RolloutPre-PCS 7 InstallationFully SupportedHigh (Automated batch)Clean installation; 100% compliant.Manual InstallationN/A (Individual VMs)Fully SupportedSlow (High labor cost)Prone to human configuration drift.

Recommended Automated Deployment Workflow via SMMC

Method 1: The Compliant Gold-Image Workflow

Build a clean virtual machine containing strictly the guest operating system (Windows 7 SP1 or Windows Server 2008 R2).
Install all verified Windows cumulative updates and VMware Tools.
Do NOT install SIMATIC PCS 7 or WinCC at this stage.
Execute Microsoft Sysprep with options /generalize /oobe /shutdown.
Convert this VM into a master VMware Template.
Clone the template 40 times. Boot each clone, assign its unique permanent Computer Name, IP address, and domain join.

Method 2: Automated Silent Rollout via SIMATIC Management Console (SMMC)

On the Engineering Station, open the SIMATIC Management Console (SMMC).
Install the lightweight SMMC Agent on all 40 target virtual machines.
In SMMC, create an automated software package task containing SIMATIC PCS 7 V8.1 SP1.
Distribute and execute the silent installation across all 40 VMs concurrently over the network.
SMMC installs WinCC and SQL Server cleanly with the correct, permanent computer names.

Verification

To verify that a deployed virtual machine operates cleanly without SQL naming conflicts:

SQL Hostname Verification: Open Microsoft SQL Server Management Studio (SSMS) on the VM. Execute query SELECT @@SERVERNAME. Confirm that the returned string matches the current Windows hostname exactly.
WinCC Activation Test: Open a test project in WinCC Explorer. Activate Runtime. Confirm that the project starts without database connection error popups.
Event Log Inspection: Check Windows Event Viewer (Application log). Confirm that source MSSQL$WINCC logs zero server name mismatch warnings.

Limitations and Operational Precautions

Resource Overcommitment: Never overcommit CPU cores or RAM on hypervisors hosting real-time PCS 7 OS Servers; assign 100% reserved memory to prevent packet loss on the Terminal Bus.
NIC Teaming Requirements: Configure redundant virtual switches (vSwitches) backed by dual physical NICs for Terminal Bus and Plant Bus networks.
Validation Requirements: In regulated industries (e.g. FDA 21 CFR Part 11), deploying via non-certified Sysprep cloning invalidates software qualification protocols.

Engineer FAQ

Why do Siemens factory restore DVDs work with computer name changes?

Siemens recovery media deploy specialized post-boot answer files that install SQL Server and bind WinCC services after the initial boot computer name prompt.

Can sp_dropserver and sp_addserver fix SQL Server after a computer rename in PCS 7?

While these SQL stored procedures update @@SERVERNAME, they do not repair the local Windows user groups or internal WinCC security tokens, leaving the installation unsupported.

Does SIVaaS support VMware vSphere vMotion (live migration)?

Yes, live migration of OS Clients is supported, but OS Servers require adherence to strict Siemens latency and heartbeat timing constraints.

Technical References

Related Tags

https://industrialautomation.net/search?query=simatic-pcs7
https://industrialautomation.net/search?query=virtualization
https://industrialautomation.net/search?query=vmware
https://industrialautomation.net/search?query=sql-server

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Virtualization and Sysprep Deployment Policies for SIMATIC PCS 7 Workstations