Network-attached storage meets the Web revolution - Industry Trend or Event

Communications News, Sept, 2000 by Jean-Yves Chevallier

Face the onslaught head-on with plenty of ammunition.

The Web revolution will thrust your information system into turmoil--once more. How much bandwidth will you need to accommodate a hundredfold increase in traffic? Can you afford to tuck your data away behind layers of servers when demand for information comes from "out there?" How do you ensure scalability, integration and quality of service (QoS)? When can you have it all ready for prime time?

To meet these challenges, you will need a whole box of silver bullets. Network-attached storage (NAS) is one of them. The vision is simple: put your storage close to its new users, right on the Web or high-speed local area network (LAN), bypassing your mainframe or multipurpose server, and guaranteeing QoS. How are you supposed to accomplish this?

Network-attached storage benefits from a fortuitous convergence of technology breakthroughs. First, available network bandwidth (Gigabit Ethernet and more) now exceeds server I/O (ultrawide SCSI or Fibre Channel). Your server can fetch data faster over the Web than on its own hard drive.

The second breakthrough comes with Linux. The hype-and-disillusionment cycle over Linux has obscured what it brings to the party:

* superior robustness due to merciless testing by thousands of developers facing all possible situations;

* modularity that allows vendors to build compact, specialized engines from the ground up, without an ounce of fat on them; and

* open source availability, creating a free market for best practices, and healthy competition among developers eager to attach their name to a successful module.

The result is a server that is, in most cases, 30% to 50% less expensive than NT for identical performance and storage capacity (and free software licensing does not hurt).

AN NAS PROFILE

There are a variety of NAS solutions available, and hundreds of qualified integrators ready to help pick what works best in a particular environment. In order to take best advantage of the technology, make certain that the solution can provide:

* a Linux-based, small-footprint dedicated operating system, with no per seat license charges;

* a universal file system allowing simultaneous access by users in multiple environments, and supporting Windows, Unix and Web (HTTP) clients, with Mac as a rare but important bonus;

* multiple RAID levels, including 0,1 and 5 data protection;

* access capacity between 60 and 100 active connected users;

* IDE and SCSI disk support, with capacities ranging from 100 gigabytes (GB) to more than a terabyte according to needs;

* integrated tape backup;

* intuitive Web browser-based management;

* support for 10Base-T and 100BaseTX;

* easy installment and setup; and

* scalability for future growth.

Midrange NAS servers vary in price according to storage capacity and motherboard components (CPU, memory). Prices can vary between $20 and $75 per gigabyte.

What's the payback on a NAS investment? The answer to this depends strongly on the user's needs, environment and the business opportunities that investment will provide. A few of the guidelines to consider, when comparing NAS against Windows NT file servers, for 100-GB servers, include:

* expect to save between $2,000 and $5,000 on purchase costs, depending on the options picked;

* unlimited server licensing and license-free clients may save another $1,000 to $3,000;

* easier setup and low administrative overhead may save about a week's worth of work over the year, which probably comes close to $2,000, factoring in overhead.

The bottom line: $5,000 to $10,000 saved for each server. If NAS is deployed on a larger scale, for instance in remote branches, savings will add up even faster.

WHERE IS NAS HEADED?

Large enterprises have embarked in rationalizing their data center storage into storage-area networks (SANs). High-end NAS (devices typically priced at more than $100,000, serving hundreds of users) are becoming SAN-cognizant. This convergence will require the industry agreeing on common standards but may affect decisions on high-end NAS purchase as early as this year.

Midrange NAS, the most dynamic market, is following a different path, as it is driven by urgent user needs more than corporate rationalization. Rapid progress is being made in two domains:

* Reliability. This is being enhanced by the availability in "budget-conscious" servers of previously enterprise-level features, such as user-selectable RAID (algorithms enabling the server to recreate data following

most hard-drive failures), hot spare (an extra disk taking over for a failed disk) and hot swap (the ability to take out and replace that same disk without shutting down operations). In 2001, NAS reliability may go to the next step, with active-failover clustering allowing two servers to back up and stand in for each other.

* Usability. NAS setup is already becoming faster and more automated, and can often be executed in less than a minute in optimal conditions, and 10 minutes when more advanced options are selected, such as insertion in an Novell directory services tree or reformatting of a RAID array.