What you will learn from this tip: NAS' early days were in the small business and departmental sector and some NAS products still offer many advantages in that environment. Here are some guidelines that
If you need a chunk of storage in a hurry for a small business or department, you're not worried about expandability and you have fairly simple storage management needs, a NAS filer can be advantageous.
A NAS filer is an all-in-one appliance that attaches to a network to provide storage capacity. A typical NAS filer can pack anywhere from several hundred gigabytes to a couple of terabytes of storage in a single package, along with network connectivity and the associated software, such as an operating system (OS). Unlike high-end NAS systems, such as gateways (which are increasingly indistinguishable from SANs) NAS filers have remained a simple, relatively cheap way to add storage to a LAN.
Since its inception, NAS has grown upwards until high-end NAS products overlapped SANs for enterprise use. However, simple NAS boxes, or 'filers', are available from many vendors. However, companies, such as Network Appliance Inc., Snap Appliance (now part of Adaptec), Iomega Corp. and Procom Technology, offer low-cost filers for small business and departmental needs. Prices for stand-alone NAS devices range from less than $1,000 to $50,000 or more, depending on capacity and features. Models are available in both rack-mount and tower, or stand-alone, configurations.
There are several advantages and disadvantages to using a NAS filer in a small business environment:
- Simplicity is one of the NAS filer's biggest advantages. A typical low-end NAS box can be up and running on a network in minutes. A NAS filer is configured to appear as a disk or a group of disks to the rest of the LAN.
- Low cost is another advantage. For example, makers of NAS filers have taken enthusiastically to SATA disks to reduce the cost of their products. Although the list price of a NAS filer is higher than a RAID array of the same capacity, the cost of integrating a NAS filer is basically nil.
- Expandability is a disadvantage, however. Generally, NAS filers have limited, if any, expandability. This is a significant disadvantatage. While most of them allow users to add disks in the box, they aren't typically designed to support external disk arrays.
- Management is still an issue, although less so than a few years ago. While storage management facilities on NAS filers have gotten a lot better, especially with the release of Windows Storage Server, NAS filers still lack the sophisticated management tools available for SANs or high-end NAS systems. Today, most NAS filers have Web-based interfaces that allow them to be managed with a browser. Even inexpensive NAS filers often include features such as snapshots, checkpoints and journaling file systems to improve data integrity.
- Backup is also a consideration. Some filers back up to an attached tape drive or library, while others can be backed up over the network. Backing up to a separate device introduces some complexity in managing backups. Backing up over the network puts an additional load on the network.
- Performance typically isn't a problem, but because they use the LAN, NAS filers are typically limited in data transfer speeds. However, many NAS filers come with Gigabit Ethernet NICs already installed and that provides plenty of bandwidth for most storage applications.
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About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last 20 years, he has been a freelance writer specializing in storage and other computer issues.
This was first published in March 2008