What does FSW mean in UNCLASSIFIED

A File Share Witness (FSW) is a special type of file server that helps to coordinate the state of a Microsoft Cluster. It provides quorum by storing information about cluster configuration and status, which allows it to detect if something goes wrong with the cluster. It also acts as an arbitrator between nodes in the cluster to ensure proper load balancing and resource availability.

FSW is typically used for high-availability scenarios, where organizations require continuous uptime for their applications or services. It ensures that the cluster remains in a consistent state even when one or more nodes fail, thereby providing redundancy and reliability. Additionally, FSW can provide other features such as automatic failover of application resources.

Using FSW has several benefits including improved stability and performance due to better load balancing of resources in the cluster; increased redundancy through multiple nodes participating in the cluster; improved scalability since new nodes can easily be added; and simplified management through automated failover mechanisms.

Setting up a FSW requires creating an additional file share on another server outside of your existing cluster configuration called a ‘witness’. This file share should then be configured to point to the current active node in your existing cluster so that it can keep its data in sync with all other nodes in the cluster. Once configured, you'll need to configure your Cluster Quorum settings so that they reference this new witness path instead of any other node or resource within your existing configuration.

In the event that your FSW fails, your entire cluster could become unstable as it will no longer have access to information about which node is actively managing each resource within your cluster configuration. Depending on how you have configured your Cluster Quorum settings however, you may still maintain access to most (if not all) services/resources within your environment until you are able to repair or replace the failed witness.

As with any system component, there are some risks associated with using FSW such as potential security issues stemming from having an additional file share located outside of your existing network infrastructure, or availability issues due to failed witness hardware/software components. However these risks can be minimized through careful planning and consideration when setting up and configuring your FSW.

There are other methods of providing redundancy for a Windows Server Failover Cluster aside from using a File Share Witness such as Node Majority Voting or Node & Disk Majority Voting. However these types of configurations typically require additional hardware such as shared disk storage which may increase infrastructure costs over deploying a traditional FSW solution.

As part of good system administration practice it's important to regularly check on the status of your File Share Witness so that you have confidence it is functioning properly and not encountering any issues - at least once per month would be recommended unless unusual events occur sooner than this which warrant closer attention.

While an external monitoring solution may prove useful for larger environments where manual checks may prove difficult (or even impossible) many smaller environments should be able to rely solely upon regular reviews and alerting through Windows Server Event Logs without needing third party solutions.

Accidentally deleting a folder containing essential components for running a successful Windows Server Failover Cluster could result in significant down time while attempting repairs - depending upon how much data was stored in this folder this could take several hours (or days) depending upon how much data needs restoring before normal operations can resume.