IP SAN for dummies.

You've seen how-to guides that take a complex topic and boil it down to a series of simple steps that anyone can follow. And thanks to iSCSI, we can take the same approach to building an IP Storage Area Network (SAN). As a matter of fact, in only a half hour you can build an IP SAN and achieve the peace of mind that your data is not only securely backed up, but also easily recovered--so you can concentrate on more resource-intensive issues in your data center.

iSCSI is an Internet Engineering Task Force (IETF) standard for transporting low latency SCSI blocks across IP networks. Simple, effective and easy to install, it uses familiar and inexpensive Ethernet technology and components like 10/100 and GigE switches, routers, VPNs, and VLANs to deliver Fibre Channel-like speed and the high performance equivalent of direct attached storage at a fraction of the cost. The result is often referred to as an IP SAN.

By adding iSCSI to your IT environment, you can quickly reap the rewards of near-instantaneous restores and significantly shorter backup windows.

iSCSI 101

iSCSI is easy to build and manage with disks that are indistinguishable from local drives, span greater distances than SCSI, and enable storage consolidation and device sharing. Benefits include:

Storage consolidation and sharing: iSCSI allows for easier management and provisioning, as well as greater scalability, flexibility and availability of data. Installing iSCSI in your data center entails minimal disruption to other applications. You can move it around easily, keeping it where you need it and not necessarily where your servers are.

Disaster recovery: Keeping your data in a remote location helps meet one of the core aspects of an effective disaster recovery plan. iSCSI makes it easy to replicate, protect and store data in different physical locations, and manage it whether you're across the street or across the country.

More powerful backup and recovery: iSCSI is ideal for facilitating immediate recovery and accelerated backup. Whether as part of a disaster recovery plan or simply because an executive needs you to retrieve a stack of data from years ago, iSCSI makes data recovery swift and seamless, while allowing you to back up data in a fraction of the time.

Low cost implementation and upkeep: iSCSI typically costs 25% less than Fibre Channel, and that cost translates to a more cost-effective IP SAN. Far greater economies are possible with careful component selection. Figure 1 shows the cost of SAN components: an IP SAN can cost about 86% less than its Fibre Channel equivalent. And because iSCSI uses well understood Ethernet technology, an IT manager will not need any special expertise or training to get the IP SAN up and running.

There are several components of iSCSI that may seem new to you, but are actually quite familiar. For example, the iSCSI initiator is the equivalent to what you use for SCSI. Host Bus Adapter (HBA) and SCSI initiators have the same basic functionality. However, instead of using HBA with all of its connectors on the back, you can use a standard RJ45 connector from your typical networking environment. iSCSI initiators are available in software and hardware. Microsoft, Linux, Novell, Solaris and AIX offer software initiators or operating system drivers. Several manufacturers develop hardware initiators or iSCSI storage Network Interface Card (NICs) including QLogic, Intel and Adaptec. Hardware initiators are recommended in IOPS-intensive applications or when CPU utilization is high.

iSCSI initiators "talk" to iSCSI targets or the storage component used at the end point of your IP SAN. In other words, the iSCSI target is disk or tape that is iSCSI-enabled so you can use it to build your own IP SAN. An effective iSCSI target delivers high-performance backup and restores, flexible connectivity for any existing storage environment, enhanced data protection features, universal operating system support, and reliability. And you shouldn't feel sticker shock as if you were purchasing a fully loaded Ferrari, remember that iSCSI is affordable.

Ready. Set. Go.

Building an IP SAN takes no time, compared to other projects like updating a Windows server with the latest fixes from Microsoft or performing daily backups. The steps are straight-forward and utilize hardware and software you're already familiar with. Figure 2 shows the IP SAN you can build using the following eight steps:

Assemble the hardware components: For building an IP SAN, you will need:

* Server

* iSCSI initiator

* CAT-5/6 cable

* GigE switch

* iSCSI storage device

Install NIC or iSCSI HBA Card in the server: Install the NIC or HBA Card just like you would any other PCI card: Open the chassis, insert the card into a PCI or PCI-X slot and run the driver installation Wizard.

Run CAT-5/6 cable from initiators to the switch: Plug the iSCSI cable from the server into the existing switch. Then connect the cable from the switch to your iSCSI storage device.

[ILLUSTRATION OMITTED]

Set up the TCP environment: Set TCP/IP subnet addresses using the typical TCP tools you use today. Using a subnet simplifies routing and delivers more security for your IP SAN.

Install iSCSI initiators: For a Microsoft server, download the file from the Microsoft website.

Configure your iSCSI storage device: Each vendor will have different configuration options. Typically, this will include volume setup to determine the physical configuration, logical volume management based on your storage capacity, device configuration to establish whether you're using disk or tape, and the connection method--which in this case is iSCSI. Define the IP address based on the TCP/IP subnet addressing that you set up in Step 3.

Partition and format the volume: After you install your iSCSI target, your new drive will appear in your file server. The next set of steps involves configuration based on your physical iSCSI storage device, and should take no more than a few minutes to move through a series of standard setup screens. Once complete, your iSCSI device appears in your operating system like any other drive does today.

Read and write to/from iSCSI SAN storage: Congratulations! You have now built a simple IP SAN and can begin to back up your data.

IP SANs in Action

Many organizations are already reaping the benefits of IP SANs. For example, a major billing and collections agency implemented an IP SAN as a result of a planned maintenance upgrade that would cut power for at least 8 hours. Its IT manager had to ensure secure backup of all of the company's data prior to the power cut. But with the high volume of data, the IT team could no longer complete full with any regularity. The company had been performing only incremental backups for months while they grappled with ways to improve the performance of their backup.

After evaluating several options, the company selected a disk-based backup appliance that uses iSCSI to provide faster backup and near-immediate restores. With the SAN installation complete, the team executed a full backup of its servers in less than 8 hours, then immediately copied the data to tape for permanent archival. When the power cut came, the team was ready. Not one file was lost, and business continued uninterrupted. The team now performs a full nightly backup--which provides much-needed peace of mind--long before even the early-bird employees begin their workday.

Conclusion

Building an IP SAN is simple, delivering seamless data protection in no time. With the high speed and cost-effectiveness of iSCSI, companies benefit from powerful backup and recovery that leaves IT teams with more time to concentrate on other critical projects. Now who's the dummy?

Figure 1: Cost of SAN components

        Component               FC Typical Price

1  Server Connectivity               $1,000
    (HBA, NICE, TOE,
          SNIC)

2        Switch                 16-port: $13,220

3        Cabling             Fiber Optic: $10/foot

4      Connectors            Fiber Optic: $22 each

   Total for 12-server  [approximately equal to] $31,000
           SAN

        Component       iSCSI Typical Price

1  Server Connectivity  10/100 NIC: $30
    (HBA, NICE, TOE,    GigE NIC: $135
          SNIC)         SNIC: $500-550
                        TOE: $700
                        Microsoft Software: Free

2        Switch         16-port: $2,000

3        Cabling        CAT-S: $1/foot

4      Connectors       RJ-45: $0.49

   Total for 12-server  [approximately equal to] $4,100
           SAN

www.overlandstorage.com

John Matze is a co-architect for the iSCSI spec, and vice president and CTO of Overland Storage (San Diego, CA)