Scale-Out File Server for Application Data Overview
Published: February 29, 2012
Updated: May 31, 2012
Applies To: Windows Server 2012
In Windows Server 2012, the following clustered file servers are available:
Scale-Out File Server for application data (Scale-Out File Server) This clustered file server is introduced in Windows Server 2012 and lets you store server application data, such as Hyper-V virtual machine files, on file shares, and obtain a similar level of reliability, availability, manageability, and high performance that you would expect from a storage area network. All file shares are online on all nodes simultaneously. File shares associated with this type of clustered file server are called scale-out file shares. This is sometimes referred to as active-active.
File Server for general use This is the continuation of the clustered file server that has been supported in Windows Server since the introduction of Failover Clustering. This type of clustered file server, and thus all the shares associated with the clustered file server, is online on one node at a time. This is sometimes referred to as active-passive or dual-active. File shares associated with this type of clustered file server are called clustered file shares.
The topics contained in this document will focus on planning and deploying Scale-Out File Server.
In Windows Server 2012, Scale-Out File Server is designed to provide scale-out file shares that are continuously available for file-based server application storage. Scale-out file shares provides the ability to share the same folder from multiple nodes of the same cluster. For instance, if you have a four-node file server cluster that is using Server Message Block (SMB) Scale-Out, which is introduced in Windows Server 2012, a computer running Windows Server 2012 can access file shares from any of the four nodes. This is achieved by leveraging new Windows Server Failover Clustering features and new capabilities in the new version of Windows file server protocol – SMB 3.0. File server administrators can provide scale-out file shares and continuously available file services to server applications and respond to increased demands quickly by simply bringing more servers online. All of this can be done in a production environment and it is completely transparent to the server application.
Key benefits provided by Scale-Out File Server in Windows Server 2012 include:
Active-Active file shares All cluster nodes can accept and serve SMB client requests. By making the file share content accessible through all cluster nodes simultaneously, SMB 3.0 clusters and clients cooperate to provide transparent failover to alternative cluster nodes during planned maintenance and unplanned failures with service interruption.
Increased bandwidth The maximum share bandwidth is the total bandwidth of all file server cluster nodes. Unlike previous versions of Windows Server, the total bandwidth is no longer constrained to the bandwidth of a single cluster node, but rather the capability of the backing storage system. You can increase the total bandwidth by adding nodes.
CHKDSK with zero downtime CHKDSK in Windows Server 2012 is significantly enhanced to dramatically shorten the time a file system is offline for repair. Clustered shared volumes (CSVs) in Windows Server 2012 take this one step further and eliminates the offline phase. A CSV File System (CSVFS) can perform CHKDSK without impacting applications with open handles on the file system.
Clustered Shared Volume cache CSVs in Windows Server 2012 introduces support for a read cache, which can significantly improve performance in certain scenarios, such as Virtual Desktop Infrastructure.
Simpler management With Scale-Out File Servers, you create the Scale-Out File Server and then add the necessary CSVs and file shares. It is no longer necessary to create multiple clustered file servers, each with separate cluster disks, and then develop placement policies to ensure activity on each cluster node.
You should not use Scale-Out File Server if your workload generates a high number of metadata operations, such as opening files, closing files, creating new files, or renaming existing files. A typical information worker would generate a lot of metadata operations. You should use a Scale-Out File Server if you are interested in the scalability and simplicity that it offers and you only require technologies that are supported with Scale-Out File Server. The following table shows the new capabilities in SMB 3.0, common Windows file systems, file server data management and applications, and if they are supported with Scale-Out File Server, or will require a traditional clustered file server:
Scale-Out File Servers are ideal for server applications that keep files open for a long amount of time, doing mostly data operations with infrequent metadata operations on the file system. Hyper-V virtual hard disks and SQL Server database files can be stored on a scale-out file share on servers running Windows Server 2012.
The following table lists the features that are part of this scenario and describes how they support it.
|Feature||How it supports this scenario|
Failover clusters added the following features in Windows Server 2012 to support scale-Out file server: Distributed Network Name, the Scale-Out File Server resource type, Cluster Shared Volumes (CSV) 2, and the Scale-Out File Server High Availability role. For more information about these features, see What's New in Failover Clustering on Microsoft TechNet.
SMB 3.0 added the following features in Windows Server 2012 to support scale-Out File Server: SMB Transparent Failover, SMB Multichannel, and SMB Direct.