By Arvind Palamadai, TME, at NetApp


This blog talks about NetApp SnapDrive for Windows and some of the exciting new features of the latest release.

What is SnapDrive for Windows?

NetApp SnapDrive for Windows (SDW) is software that helps you to perform storage provisioning tasks and manage data in Microsoft® Windows Server environments. You can run SnapDrive on Windows hosts in physical, virtual and private cloud environments. SnapDrive integrates with Windows Volume Manager so that storage systems can serve as virtual storage devices for application data in Microsoft Windows Server® 2008 R2, Windows Server 2012, and Windows Server 2012 R2. You can also use it to provision storage for Windows Virtual Machines (VMs) hosted on Microsoft Hyper-V or VMware ESX® hypervisors.

SnapDrive manages LUNs on a storage system, making those LUNs available as local disks on Windows hosts. When installed on a Windows Virtual Machine (hosted on Microsoft Hyper-V or VMware ESXi), you also have the ability to provision Pass-through disks/RDM LUNs using SnapDrive and VMDKs in conjunction with VSC.

SnapDrive can provision ISCSI, FC, FCoE disks from a NetApp storage array. It can also provision SMB 3.0 Shares to support Microsoft Hyper-V® over SMB and Microsoft SQL Server® over SMB workloads.

Key Features of SnapDrive for Windows

SnapDrive for Windows provides the following features in Clustered Data ONTAP® environments:

  • Integration of Data ONTAP Snapshot technology with the Microsoft Volume Shadow Copy Service (VSS) framework and thus creation of point-in-time images of data stored on LUNs.
  • Supports Microsoft cluster configurations.
  • Support for iSCSI, FC, and FCoE in Windows and VMware® environments.
  • Support for virtual Fibre Channel adapters for guest virtual machines running Windows Server 2012 and above.
  • Support for raw device mapping (RDM), virtual machine disk (VMDK) over the Network File System (NFS), and Virtual Machine File System (VMFS) datastores in VMware environments.
  • Native NetApp SnapVault® integration.

New features in SnapDrive for Windows 7.1

The latest release of SnapDrive for Windows has a host of new features and enhancements which are a great value add for any Windows administrator. For a list of What’s New in SnapDrive 7.1, please refer to the Release Notes.

Some of the New Features and enhancements of SDW 7.1:

  • Clone of Clone
  • Split-Clone
  • Dedicated disk behavior

Clone of Clone

The Clone of Clone feature enables you to provision a volume, create a Snapshot copy of the volume and then clone the volume using the Snapshot copy. Data ONTAP creates the new volume from the Snapshot copy, and the new cloned volume, shares the underlying blocks of the original volume. This volume clone can be re-cloned to create another instance of the dataset, and mounted to a host. SnapManager for SQL Server uses the clone-of-clone functionality to clone the data for testing and development purposes without the need for massive incremental storage.

There are a couple of things to remember before you plan to use this feature are:

  • By default, SnapDrive supports only two levels of clones; however, in the case of VMDK on VMFS, more than two levels can be created.
  • Make sure that there is adequate space in the aggregate for clone operation to succeed.

Split Clone

This feature enables you to split the volume clone from the parent volume and make the volume clone an independent NetApp FlexVol® volume. All SnapManager products make use of the split-clone feature. When the Snapshot copy is mounted as a FlexClone volume, the volume clone depends heavily on the parent volume because the blocks are shared. The split-clone feature allows you to remove the dependency of the FlexClone volume by splitting the clone from the parent. Data ONTAP supports the split-clone feature.

Few things to remember before you plan to use this feature are:

  • During a volume clone split operation, LUN provisioning and Snapshot management operations are not supported on the affected volume.
  • Use the sdcli clonesplit status command to determine the status of the split-clone operation.
  • Ensure that the aggregate has adequate space for the split-clone operation.
  • Split-clone operations take considerable time (a 1GB volume clone split operation takes 5 minutes)

Below figure shows the clone-of-clone and split-clone features.



Dedicated Disk Optimization

Prior to SnapDrive 7.1, in a Windows clustered environment all nodes required SnapDrive to be installed, with proper network connectivity to the storage, for creation of a “dedicated disk”.

With SnapDrive 7.1 for Windows, SnapDrive is needed only on the cluster node on which the dedicated disk is created. This feature enhancement improves productivity of the administrator as it reduces the time it takes to map disks to all the cluster nodes.

Note: This change is applicable to Windows Server failover clustering environments, and it is specific to dedicated disks.

This enhancement applies to Microsoft Exchange database availability groups, SQL Server availability groups, and mixed storage environments in which SnapDrive and SnapManager will be used only in certain nodes in the cluster.

Challenges and Use Cases

Cloning of databases is something every DBA does on a weekly or monthly basis on request from test and development teams. During my DBA days, the turn-around times for such tasks was 3-4 hours. My previous organization followed an agile development, test and support model. It was critical to be able to provide clone of web applications and SQL databases to the support & development teams. The development teams had their own turn-around times to fix critical bugs and the faster I could provide them what they needed, the easier it was for them to meet the client SLAs.

When I read about the Clone of Clone and Split Clone features of SDW, I was excited to the test the same with a test SQL Server deployment. I installed a single instance SQL Server 2012 on Windows Server 2012 R2. I created a new database on a NetApp FAS3170 LUN and pumped some sample data on the database.

Using SnapDrive’s Clone of Clone feature I cloned the disk on which the SQL data and log files resided. Once the clone operation was successful and the drive mounted on the Windows machine, I could use the data file to create a fresh copy of the database from SQL Management Studio.

Note: SMSQL uses clone feature of SnapDrive while cloning of databases.

This operation takes only a few seconds and a clone of the production database or applications can be done in a matter of minutes. In scenarios where extended teams end up using the cloned database or applications for extended periods of time, the administrator can choose to Split the Clone Volume so as to remove the dependency on the original NetApp FlexVol.

Hope you got a gist of the new features explained in this blog and will use them effectively in your environment.

For some of the best practices for using SnapDrive for Windows please refer to the following TRs.

NetApp Staff