What you will learn from this tip: This tip looks at how network attached storage (NAS) can be used to address file management woes as well as how to tame NAS and file server sprawl.
Managing files is the bane of many IT server and/or storage administrator's existence. The number of files on servers and desktops not only keeps growing, but so does the size of those files. If that weren't enough, administrators have to determine where to place all of these files, and ensure they're secure and backed up, which in turn results in more copies of files being made.
The techniques and approaches to address network attached storage (NAS) sprawl are similar to those used to tackle PC sprawl in the past, ranging from zero tolerance to ignoring the problem. Consolidation of NAS systems and NAS virtualization can be used to tame NAS sprawl, including addressing data protection and backup requirements.
Standalone NAS appliances are easy to use because they're self-contained and often preconfigured for rapid installation. This ease of use, however, combined with limited scaling capabilities of some appliances has contributed to the sprawl of NAS and file servers. Consolidation of NAS and file serving systems includes leveraging larger higher performance systems like those from BlueArc Corp., EMC Corp. and NetApp Inc., among others. Another consolidation approach is to leverage NAS gateways from vendors including BlueArc, EMC, NetApp and ONstor among others. If you have an existing storage area network (SAN), you may want to consider deploying a NAS gateway to improve storage utilization and enhance your overall return on investment. By understanding the performance characteristics (such as I/Os, bandwidth and response time) of target applications, you can determine if you have adequate available network bandwidth to support these and other applications on NAS.
Yet another approach is to use clustered and parallel access systems from vendors including Exanet Inc., Ibrix, Isilon Systems Inc., Polyserve Inc. and SGI.
New technologies are addressing the challenges associated with NAS sprawl and the protection of remote-office data. NAS virtualization (also known as NAS aggregation or global namespaces) is analogous to block storage virtualization and addresses similar management issues, including virtualized access, transparent data movement and migration. Vendors include Acopia Networks Inc., Attune, Brocade Communications Systems Inc., EMC/Rainfinity and Neopath Networks Inc.
Data preservation, integrity and retention features to look for include: RAID-5 or dual parity schemes (like RAID-6) for data availability and accessibility of 750 GB 3.5" SATA disk drives; WORM and transparent data archiving capabilities; and regulatory compliance features. Given the sensitivity of legal documents, applicable NAS products should provide adequate security to meet information privacy concerns.
When determining how much storage is needed, keep the number, and the size, of your files in mind. From a performance standpoint, consider how many files will be open at any given time, and the amount of read or write I/O activity that will take place along with random vs. sequential I/O patterns. I/O characteristics vary by application, ranging from small .jpg or .tif files, to high-speed data acquisition cameras that require a large file system. If you're streaming data, you'll be dealing with large sequential read and write I/Os.
If your applications require performance, storage capacity or availability beyond the limits of a standalone NAS appliance or NAS gateway, you should consider a clustered NAS product for scalability. NAS clusters cannot only benefit administrators consolidating several standalone NAS appliances or servers to simplify management; they can improve availability and resource sharing. Clusters are also useful when it comes to supporting high-performance or storage-intensive audio, video, imaging and fixed-content applications.
Regardless of how it's implemented, NAS is a great cure for your file- and storage-sharing headaches. Exercise care and moderation with NAS, and you'll avoid even bigger headaches down the road. Learn more about NAS and file management options in the WinStorage magazine June 2006 article "NAS helps tame rampant file proliferation.
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About the author: Greg Schulz is founder and senior analyst with the IT infrastructure analyst and consulting firm StorageIO. Greg is also the author and illustrator of "Resilient Storage Networks" (Elsevier) and has contributed material to "Storage" magazine and other TechTarget venues.
