NetApp moves toward storage grid

Launches Data ONTAP 7G

By Heidi Biggar

Network Appliance last month announced the 7G version of its Data ONTAP operating system and, in doing so, marked a significant milestone in its pursuit of a storage grid architecture, according to analysts. Data ONTAP is the operating system that runs on all Network Appliance filers and storage systems. The acquisition of Spinnaker Networks last February launched NetApp into the storage grid arena.

NetApp is in the process of integrating the Spinnaker technology-including the SpinFS distributed file system, clustering, and global namespace-into both its ONTAP operating system and WAFL (Write Anywhere File Layout) file system. The Spinnaker technology is central to the company's future storage grid capabilities, say analysts.

"Data ONTAP 7G provides the fundamental building blocks for a grid-type of architecture going forward," says Brad Nisbet, program manager for International Data Corp.'s (IDC's) storage systems program.

The fundamental building blocks of this software release are FlexVol and FlexClone, which are designed to help users address the rising management costs of storage environments, claim NetApp officials. The Gartner IT consulting firm says the cost of managing storage may be up to four times that of the per-gigabyte cost of the storage hardware.

"FlexVol and FlexClone address the costs of managing storage," says Suresh Vasudevan, senior director of software at Network Appliance.

FlexVol allows users to create virtual pools, or containers, of data within single NetApp storage systems or in clustered pairs, which can be dynamically shrunk or expanded as needed. FlexClone automates the manual task of making multiple copies of application datasets for testing or simulation purposes without the typical storage overhead associated with traditional approaches, says Vasudevan.

"In industries like financial services and telecommunications, there is a ton of time spent on application development and deploying applications," explains Vasudevan, "and you usually see three to nine copies of production data, which means that you typically have three to nine times the amount of storage capacity."

FlexClone eliminates the need for any significant additional storage overhead and speeds testing time by making "writable" snapshots, which only consume additional storage space when changes are made to the datasets.

"FlexClone extends the concept of snapshots by creating 'writable' rather than 'read-only' copies of application datasets," says Vasudevan. "The amount of storage capacity that is consumed is significantly less than with traditional cloning techniques and the process of cloning is almost instantaneous."

As an example of the inefficiency of most application development processes today, SAP estimates that about 70% of its licenses relate to test environments while just 30% are being used for primary production purposes, according to Vasudevan.

But while both FlexVol and FlexClone are integral parts of NetApp's storage grid vision, FlexVol, not FlexClone, has captured the attention of analysts.

"Thin provisioning is one of the most useful features that storage vendors can implement because it solves two major problems that administrators face: storage provisioning and capacity planning/utilization," says Tony Asaro, senior analyst at the Enterprise Strategy Group (ESG) Lab.

While NetApp is the first large storage vendor to offer "thin provisioning," the technology is not new to the market. Thin- provisioning technologies are also available from smaller vendors such as Compellent, LeftHand Networks, and 3PAR, which pioneered the technology. "3PAR has been the leader in bringing this functionality to market," says Asaro.

The power of "thin provisioning" is that it allows users to allocate large, logical volumes from a common pool among multiple applications. However, actual physical capacity is not consumed until an application actually writes data to the disk array (see "3PAR streamlines provisioning," InfoStor, May 2004, p. 8).

"With FlexVol, a system administrator can allocate 1TB to a volume, but it is not committed and cannot be used by any other application," explains ESG's Asaro. "The application sees 1TB but only uses, say, 100MB of actual physical storage. As more data is stored by the application, it just takes it from the pool of storage as needed."

This type of process can help users from over-provisioning capacity to applications. Analysts say that this approach has significant benefits over other approaches from vendors that simply automate the provisioning process (e.g., the workflow process, scripting, etc.).

By managing data, not disks, in this fashion NetApp's Vasudevan claims users can boost capacity utilization from less than 50% to more than 80%. "You start with the same physical storage, but instead of mapping volumes on drives you treat them as flexible entities," he explains.

Doing so also allows users to create volumes on demand and with their own set of policies for various storage services (e.g., synchronous/asynchronous replication, etc.). FlexVol also automatically shares spindle performance among all data volumes, regardless of the size of the volume. "This means that very small data sets can leverage the performance of a greater number of spindles without all the management headaches of manual approaches," says Vasudevan.

NetApp officials claim users will generally see a greater than 2x improvement in performance without any of the management headaches associated with traditional techniques.

Separately, Network Appliance also announced several enhancements to its gFiler NAS gateways, including Fibre Channel data access, support for HP StorageWorks XP disk arrays and IBM TotalStorage DS4000 series arrays on the back-end, as well as support for the new version of Data ONTAP, which, among other things, will allow users to perform operations such as replicating from gFiler to gFiler, or gFiler to NearStore systems, without using any software tools on the back-end disk arrays.

The gFiler previously supported back-end storage arrays from Hitachi Data Systems, Hitachi Ltd., Sun (StorEdge 9900 family), and IBM Enterprise Storage Server (ESS) disk arrays.

A competitive product to NetApp's gFiler is ONStor's SF4400 SAN Filer. While the ONStor product currently does not support "FlexVol-type" capabilities, it does provide a variety of other storage applications, including ONStor Data Mirror, High Availability, SAN Filer Manager, and Load Balance (see "ONStor delivers SAN-based file services," InfoStor, January 2004, p. 12).

According to analysts, gateways will potentially compete with intelligent switches as a file-level (versus block-level) way of moving, managing, and accessing data in the fabric. (For more information on NAS gateways, see "Gateways bring NAS into the data center," InfoStor, November 2004, p. 20.)

This article was originally published on December 01, 2004