NAS, or network attached storage, is a must-have for large sites that require access to significant amounts of data or where data is being shared among multiple systems, such as in a data warehousing environment. But how do you decide which NAS product best suits your needs? For those who are new to the NAS market, I will introduce four big players in the NAS market:
- Network Appliance
While I realize that there are many other companies that offer this type of service, these are four of the biggest vendors, and taken together, they represent a large majority of the NAS market share. They also make up the list of “usual suspects” when purchasing decisions are made. I will present an overview of each vendor's product line, along with its strengths and weaknesses, and offer a quick comparison of features.
Where is NAS needed?
Before I discuss individual companies and products, let’s take a look at some of the typical places where NAS can be a great benefit. NAS becomes both useful and cost effective in a number of areas.
- In a heterogeneous networking environment where multiple operating systems are in use, it can be easier to supply central storage rather than try to maintain it across each individual OS, especially since some of the NAS devices can natively support each OS.
- In a hosting environment where farms of servers are used to provide Internet services, it is likely that each Web server needs access to the same data. Rather than replicate the data to each server, it’s easier to store everything centrally.
- For environments where huge amounts of disk space are required, a NAS device may be the only option, since its capacity generally surpasses that of local server storage.
EMC provides a whole host of storage solutions, including Fibre Channel, but I'll focus here on its enterprise storage platform offerings. While EMC’s main focus is in providing services to larger organizations, it also has products targeted at the smaller ones. EMC’s CLARiiON systems, acquired when EMC purchased Data General a few years ago, provide many of its higher-end products.
EMC’s products incorporate disaster recovery and high-availability options called SnapView and MirrorView, respectively. SnapView takes a point-in-time snapshot of the protected disk contents, while MirrorView does exactly what it sounds like—mirrors critical data to another device, which takes over during a failure.
The higher-end EMC unit, the CLARiiON 4700 series, supports up to 8 TB of reliable, highly available storage and supports a number of operating systems, such as Windows, NetWare, UNIX, and Linux.
On the lower end, EMC offers the Celerra line of NAS servers, which still implement some of the features of the high-end devices, such as the SnapView functionality.
Network Appliance provides devices that run the gamut from a workgroup server, the NetApp F87 supporting up to 576 GB, all the way up to an enterprise-class device, the F880c supporting up to 12 TB (18 TB in the future).
Network Appliance’s products are generally considered very stable and reliable. They feature snapshot technology that allows a point-in-time restore of selected data in the event of a data loss. In addition, Network Appliance filer heads, which control the disk arrays, can be connected together in a redundant network and take over for each other in the event of a failure. With the technology available in Network Appliance filer’s data ONTAP software, which manages the filer, data protection and high availability are both provided.
Network Appliance filers also support multiple-protocol access to the stored files. CIFS (Common Internet File System—better know as SMB), NFS, and HTTP are all supported by the filer but may require the purchase of additional packages.
Table A shows an overview of the capacity of the Network Appliance product line.
|F880||6 TB (9 TB in the future)|
|F880c||12 TB (18 TB in the future)|
For small to midsize organizations, there is Quantum, with its line of Snap Servers. The Quantum Snap Server line is a veteran of the NAS market and has the strength of longevity behind it. While the Snap Servers don't have the high-end tolerance and availability features of EMC and Network Appliance products, that is not what they are designed for. (Quantum has begun to roll out some higher-end NAS products.) Snap devices are generally designed to replace slower, more expensive file-server-based file storage solutions by using an appliance device custom-made to perform nothing but file serving.
Ranging in size from 40 GB to almost 1 TB, a Quantum Snap Server can be found that will supplement almost any small or midsize organization's file storage needs. Quantum Snap Servers are designed for low TCO, and they also feature low acquisition cost (starting at $500). Further, Quantum likes to tout the ease of installation, claiming that the units install in just minutes, which is true.
The Snap Servers support an impressive array of protocols, allowing them to interoperate with a number of operating systems. They support CIFS/SMB, NetWare’s NCP, NFS, AppleTalk Filing Protocol, HTTP, and FTP. The units can take part in Active Directory to integrate with Windows 2000 and can also emulate a NetWare bindery to more easily interoperate with NetWare. While NDS integration and emulation of a NetWare server greater than version 3.12 would be much better for the folks running that OS, the low cost of acquisition may offset that drawback for many organizations.
Somewhere between EMC and Network Appliance on the high end and Quantum on the low end, there's Maxtor. While Maxtor offers many solutions for small to midsize businesses, it also offers solutions containing some of the higher-end features found in the EMC and Network Appliance solutions, such as snapshot capability.
The two primary NAS product lines from Maxtor are the MaxAttach 4000 and the MaxAttach 6000. The MaxAttach 4000 series is aimed for the lower end, with capacities ranging from 320 GB to 640 GB, while the MaxAttach 6000 series ranges in capacity from 1.9 TB to 5.7 TB, clearly putting it out of the low-end league.
Like the other vendors, Maxtor’s devices are designed to support a heterogeneous environment made up of Windows, NetWare, and UNIX/Linux servers, among others, and they're capable of communicating via TCP/IP, IPX/SPX, AppleTalk, and HTTP. While this vendor supports Active Directory integration, it does not integrate with NDS. Table B shows the capacity of Maxtor devices.
|NAS 4100||320 GB|
|NAS 4300||640 GB|
|NAS 6000||5.7 TB|
We have introduced you to some of the offerings that are available in the NAS marketplace on both the higher end and the lower end of the spectrum. Other vendors, such as Dell and Compaq, are rolling out storage solutions as well, and they will be worth a look. However, if you're ready to implement NAS, any of the four vendors mentioned in this article can definitely serve you well.