Foundations of
Network Storage: Lesson 1 of 5.

In this lesson, we’ll
explore the storage area network (SAN). Topics include how to decide if a SAN
is best for your organization, your choices regarding SANs, and the tools you need to support a SAN.

A Storage Area Network is the most expensive storage option available,
as well as the most complex. However, SANs provide
capabilities not found in other solutions and, in the right situation, can help
you improve the bottom line, even considering the expensive initial outlay.

SAN advantages

SANs today come in two flavors:
Fibre Channel, and iSCSI or IP-based SANs. Fibre Channel is the most well known type of SAN, but
over the last couple of years, iSCSI-based SANs have started to hit the market in a big way, mainly
due to their good performance and much lower cost versus Fibre Channel.

SANs truly combine the best of
both NAS and DAS storage. For example, with a proper implementation, you get a
completely redundant storage network that is eminently expandable to,
literally, hundreds of terabytes a la NAS, but you also get block-level access
to the data just as you get with DAS. You can also access data at a reasonable
speed, making SANs good even for operations that require
significant disk access. With a SAN, you also get centrally managed storage
with the ability to provision space on-the-fly. Even better, with some
implementations, you can configure your servers with no internal storage and
require that all systems boot directly from the SAN (Fibre Channel only). Talk
about plug and play!

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SAN drawbacks

With all of these great points, what are the downsides of a
SAN? There are two major drawbacks to a SAN: cost and complexity, particularly
when it comes to Fibre Channel implementations. A reasonable Fibre Channel SAN
can start in the $50-60K range for just a terabyte or two of storage. On the
other hand, newer SANs based on iSCSI
might start in the $20-30K range, but aren’t quite up to the performance levels
of their Fibre Channel cousins. The difference in price is mostly due to iSCSI’s ability to make use of off-the-shelf gigabit
Ethernet hardware, whereas fibre channel requires specialized, expensive
equipment.

For a collection of resources on Storage Area Network, see
page two.

SAN Resources

  • Make the best
    SAN choice with this storage comparison chart
    This downloadable chart provides a quick-glance
    comparison of some of the storage products and servers available from
    Dell, HP, and IBM, and lists specifications and features for
    direct-attached SCSI storage, NAS, iSCSI, and
    fiber-channel-based SAN solutions.
  • From
    Microsoft.com: Microsoft
    Windows Clustering: Storage Area Networks
    This document describes what storage area networks (SAN) are, how server
    clusters can be deployed in a SAN, and how the Windows platform, and
    Windows clustering in particular, take advantage of SAN technology.
  • Storage
    Basics: Storage Area Networks
    This article introduces the SAN and examines its role in modern network
    environments and whether it meets the storage needs of today’s
    organizations.
  • Planning
    storage solutions that grow with your business
    Choosing the right storage solution for
    your growing business isn’t a “no brainer.”
    You have more choices than ever, and scalability and performance must be
    weighed against ease of use and the ever-present budget considerations.
    Here’s how planning now can save you money in the long run.
  • Case study:
    Using a SAN to increase uptime and decrease backup times
    An IT manager at a healthcare company decides not to go with a
    low-cost solution such as network attached storage devices. Instead, he
    opts for an expensive SAN. Find out why knowing the business implications of this decision lets the investment pay
    off.
  • Webcast: SAN
    Lessons Learned
    When Brocade Director of IT, Jim Ravelli, implemented
    a SAN last year, he went through many of the same steps you might
    encounter in migrating to a SAN architecture. In this free webcast “SAN Lessons Learned,” Jim will
    describe the Brocade IT environment before the SAN, and the steps involved
    in implementing and managing the SAN to support mission-critical
    information and applications.
  • Discussion:
    SAN backup drive being fragmented. Should I defrag?
    A TechRepublic member has 16 drives in the SAN with about 1tb of space,
    split into two logical drives for access for two separate servers. One of
    the partitions is badly fragmented. Should he be running defrag on these
    drives? Read what another member advised.
  • Discussion:
    Multi-server reads to same set of SAN disks
    Is it possible to store a single copy of the same read-only content within
    an EMC SAN (DMX2000 and DMX3000) and allow multiple servers to read the
    content?
  • Blades break down
    barriers
    In the traditional data center, storage, network
    and server experts don’t tread on each other’s turf. But as these tiers
    converge in blades servers, there’s potential for a big shake-up. Tim
    Golden, director of PowerEdge server marketing
    for Dell, explains in this Whiteboard Video.

White Papers

  • Improving
    SAN Performance and Reliability With the NetWisdom SAN Performance Monitoring Tool
    NetWisdom can be used to develop a SAN
    performance baseline and verify that the SAN is performing as expected
    according to the baseline. Using the performance baseline, SAN
    administrators can establish a service level agreement with customers and
    measure the SAN performance against this SLA.
  • Choosing
    the Best Architecture for Data Protection in Your SAN
    Download this HP white paper to learn more about the factors that
    contribute to the notorious lack of reliability in SAN-based backup
    solutions and why a growing number of enterprises are solving that problem
    by deploying intelligent, controller-based tape library architectures.
  • SANFS
    Maestro: A SAN File System Planner
    Manual planning of storage infrastructures that are large and that utilize
    heterogeneous devices has become a time consuming and error prone process.
    This problem becomes even more complex when one is designing storage area
    network file system (SAN FS) based storage solutions. SAN FS systems that
    combine the benefits of both SAN and network attached (NAS) systems have
    been proposed as a mechanism for designing scalable storage
    infrastructures. This paper proposes a SAN FS capacity planning tool that
    takes application level requirements, best practices, and other types of
    policy input to design the necessary SAN FS logical and physical
    constructs.

SAN Vendors

Course list

  • Lesson 1: SAN
  • Lesson
    2: NAS
  • Lesson
    3: Fibre channel/iSCSI
  • Lesson
    4: Backup
  • Lesson
    5: What’s next?

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