NAS is available in a wide variety of sizes, prices and levels of sophistication. It ranges from single-drive enclosures that start at less than $200 to systems that can accommodate hundreds of drives and offer the same levels of sophistication as Fibre Channel storage area network (SAN) systems at prices that can easily exceed $100,000.
This review will look at several representative samples, from the simplest single-drive system from Western Digital Corp., to four-drive systems from Buffalo Technology Inc. and Synology Inc., to a Reldata Inc. 9240 system that supports dozens of drives, using multiple 12-drive enclosures.
There are several things that you get with more expensive systems. The first is redundancy -- losing one drive (or more than one drive, depending on the configuration) will not cause data loss. You will also get more sophisticated choices for making the storage work well with existing systems. This provides the ability to import user and group information from Windows Active Directory or other Lightweight Directory Access Protocol (LDAP) systems, support for NFS, the networking file system used by Unix and Linux, as well as the Windows CIFS system, and support for different RAID levels.
Beyond this, the most sophisticated systems offer an selection of specialized features, from multimedia support to replication that allows you to create backups on other systems or at other locations that are always up to date.
The Western Digital MyBook represents the simplest sort of NAS, which is really intended for home users or very small offices. With one or two drives, an easy setup and a basic feature set, it is inexpensive and quick to deploy, but limited in capacity, expandability and advanced features.
The TeraStation from Buffalo and the Synology RS407 are midtier systems, with more features, a modicum of expandability and are priced at less than $1,000. The Reldata 9240 Storage Gateway is an advanced system suitable for large enterprises or smaller companies that expect a lot of storage growth in the near future. The 9240 offers a high degree of expandability, the ability to replicate data to another storage array for fault tolerance, to upgrade from Ethernet-based NAS to Fibre Channel for additional performance, and other high-level features. Pricing starts at $29,000.
None of these products are unique, although the Synology RS407 comes the closest, with file server and Web server functionality, as well as multimedia features. There are many comparable models to all of the ones tested, with generally similar features. But performance can vary widely depending on the speed, disk interface and number of the disks in the system.
This is true even with various models from the same vendor. The Reldata 9240, for instance, is available with anywhere from three to 16 disks, and the disks can be 7,200 RPM SATA drives or 10,000/15,000 RPM serial-attached SCSI (SAS) drives.
It is impossible to give one number for performance. In general, a one- or two-drive system like Western Digital's MyBook will only be suitable for backing up desktop or laptop systems. Systems like the Buffalo and Synology four-drive systems will easily handle the needs of a branch office, and systems comparable to the 9240 will handle the needs of even large data centers.
Western Digital MyBook World Edition WDG1NC5000N
The Western Digital MyBook World Edition is the most basic of NAS systems, a small enclosure with a single drive, an Ethernet port and a USB port that allows expansion via a USB-attached external hard drive.
Once the initial setup is accomplished, the drive is available as a Windows file share, and is available to be used by any authorized user on the network. Initial setup is done via proprietary software rather than a Web browser, but once the system is configured, any system can access the drive without additional software, and there is an administrative browser interface available, although the documentation doesn't recommend it.
MyBook is not configured to connect to an Active Directory network. It does support the workgroup mode for connecting multiple PCs.
The box itself has an indicator showing how much of the drive is in use, and a hardware reset button allows you to change the administrator account and password back to the defaults if necessary. The included backup software allows users to back up files or directories on local PCs to the MyBook. WD Anywhere Access software allows you to share files on the drive with up to five users anywhere on the Internet.
There is also a MyBook World Edition II that features dual drives. The default installation spans the drives in a RAID 1 configuration, which gives you the most capacity, but that means if either drive fails, all data will be lost. You can change the RAID level to RAID 0, which halves the capacity but will preserve the data if either drive fails.
While it's intended primarily for home use, Western Digital's MyBook is small, quiet and inexpensive, and a good fit for small branch offices. The WDG1NC5000N street price is $129.99.
Buffalo Technology Inc. TeraStation Pro II
The TeraStation is a relatively small tower configuration, and is very quiet, making it suitable for a small office without a separate server room. Buffalo also offers a rack-mount version. Both support up to four drives, include a simple and straightforward configuration but with a GUI that allows for a wide variety of configuration options, too.
Initial configuration of the system requires installation of Buffalo's proprietary software to find and perform basic network configuration. After that, the rest of the configuration can be completed via browser. When attempting to join an Active Directory domain, the Buffalo software refused to accept the domain password, saying it contained invalid characters. Once I changed the password to one it preferred, joining the domain went smoothly.
The TeraStation offers RAID 0, RAID 1 or RAID 5 with a simple configuration that defaults to RAID 5. The TeraStation doesn't offer all the bells and whistles of the Synology unit, but is also 15% less expensive.
The suggested retail price for the 1 TB TeraStation Pro II is $799.99. It is suitable for small office environments up to a couple of dozen users, and will easily provide shared file functionality as well as enabling regular backups of desktop systems.
The Synology RS407 is an small to midsized business (SMB)-oriented appliance that is simple to configure and get running. I received a 1U rack-mount system, but Synology also offers the system in a tower configuration. They run quietly, making them suitable for small offices without separate server rooms.
The RS407 also includes a wide variety of extra features. They include support for both Windows Active Directory and Macintosh networks; Unix/Linux support via FTP; the ability to add external drives to increase capacity; support for RAID levels besides the default RAID 5; and backup services.
It also offers a Web server, and some unusual Web services features that enable multimedia file sharing, audio streaming to the iTunes client, browser-based file sharing, dynamic DNS support for sharing files over the internet, and even a feature that enables recording video from IP cameras.
Setting up the RS407 is accomplished in two steps, first by running the Synology application on a local computer, and the rest via a browser. Unlike the Buffalo product, the Synology application doesn't install anything on the workstation -- once the initial configuration is accomplished, you can remove the CD and there's no impact on the local PC.
In addition to the initial configuration application, the CD also includes data replication software and peer-to-peer acceleration software that facilitates file downloading from the Internet to the RS407. The RS407 also supports sharing external USB and eSATA disks, and USB printers, making it a full-service file/print/Web server for small organizations.
The Synology backup software offers both scheduled backups from multiple PCs to the RS407 as well as synchronization, which backs up any changed files, ensuring that changes aren't lost between the time the file is changed and the time of a scheduled backup.
The RS407 suggested retail price is $949, a relative bargain if you can use the additional Web, file and print server functionality included with the system. With the RS407 and a router, you could set up a complete small business network at a reasonable price.
Reldata 9240 Storage Gateway
The Reldata 9240 Storage Gateway is not a simple self-contained NAS system. It is a highly configurable, expandable system that can connect to up to several dozen drives and make them available as either NAS (over Ethernet) or SAN (via Fibre Channel).
You can run one controller or dual controllers for redundancy, and the system offers features that you might find on competing systems from EMC Corp., Compellent, NetApp, Xiotech or other vendors. Along with the sophisticated functionality, however, comes the need for a more sophisticated administrator. This system doesn't have the simplified, streamlined interface you'll get with the Buffalo or Synology systems.
When initially configuring the 9240, setting the IP address of the administrative interface can be accomplished via the control panel on the front of the system. Once the first IP address is set, administering the Reldata 9240 requires downloading a Java application to your browser.
Once that is done, the rest of the configuration can be done through your browser. The interface is not difficult to navigate, but it is more complex than the other products tested. Getting a volume defined and available to end users requires quite a few more steps than the other systems, even using the wizards built into the system.
I found it quite difficult to get the 9240 to work with my existing Active Directory server to set up users and groups to allow access to the 9240. I was eventually able to get it to work, but it took more experimentation and even reading the manual. The wizards take you through the process of creating a volume and making it available, and work well.
Beyond the basics, the 9240 offers functionality such as replication and snapshots. The 9240 also offers automation functions that can script actions such as taking snapshots. These options are available at additional cost, but add capabilities for business continuity and disaster recovery suitable for even large organizations.
The price for a NAS-only Reldata 9240 Storage System with 6 TB of SATA storage starts at $29,000. A 10 GbE option is available for $7,995. There is no limitation on how many drives can be supported by a Reldata 9240 Gateway. The storage system has the limitation of 48 drives (single or dual controller plus three JBODS) 12 drives each.
The 9240 is not simple, nor is it inexpensive, but it can give you levels of availability and performance not possible with the smaller systems.
This was first published in July 2008