Ben Franklin said death and taxes are the only two certainties in life. We'd respectfully add a third: Your business will need more storage 12 months from now than it does today. For small and midsize enterprises, buying more servers or shifting data to less-than-desirable locations to relieve the space crunch is a stopgap, not a strategy. If you're stressed about the scalability of your server-based storage options, maybe it's time to consider a SAN.

Five years ago, the thought of an SME deploying a SAN was laughable because of the expense of a Fibre Channel infrastructure. That's no longer the case, thanks to the iSCSI protocol, which lets block-level data travel via TCP/IP. Dell's newest product, the PowerVault MD3000i, is aimed at cost-conscious businesses that are ready to graduate from direct-attached storage to a centralized strategy using iSCSI.

Dell isn't the only vendor chasing this lucrative market. Other options include EqualLogic's PS70E/PS100E, Hewlett-Packard's MSA 1510i, LeftHand Networks' NSM 160, and the Network Appliance FAS270. Dell's MD3000i, which starts at $8,000, compares favorably on price and features, but it has drawbacks, mainly a limited capacity for snapshots and no current support for SATA drives.

WHO YOU CALLING SCSI?

We can forgive some omissions because the MD3000i strikes an even balance between features and price. Automated input/output path failover, automatic array failure detection, and rebuild using a standby hot spare are available out of the box. Niceties like snapshot and volume-copy functionality can be had as software upgrades.

We were very impressed with the simplicity of Dell's MD Storage Manager application. The Java-based management GUI was very simple to navigate and performed on par with a client-server application. As for setup, we managed to rack and configure the device and get a server connected to an array in just one hour. We opted to read the manual, but if you're pressed for time, Dell offers a Remote Implementation Service in which a technician connects to your management station via WebEx and guides you through configuration of your array and host servers. Best of all, RIS is free.

We were comfortable installing the SAN ourselves, but we decided to put RIS to the test and were very impressed with how quickly an engineer completely configured our SAN and trained us on product functionality. This is definitely a major value-add, especially for smaller organizations with overstretched IT staff. On-site installation is also available for a fee.

Easy installation and a slick GUI are nice, but they're all for naught if the product doesn't meet expectations. Fortunately, the unit's performance impressed us, too. We copied a 500-Mbyte file from an iSCSI-connected server to our test PC within seconds. All four of our iSCSI ports were linked to an Extreme Networks 24-port Giga- bit Ethernet switch, which served as our back-end SAN switch fabric. While the MD3000i doesn't specifically require Gigabit Ethernet, it is strongly recommended.

We also compared the MD3000i to an EMC Fibre Channel SAN. Test clients saw no difference in performance copying a 500-Mbyte file from an EMC Fibre Channel SAN vs. the Dell MD3000i IP SAN. As long as your back-end network infrastructure that acts as the SAN fabric can support the necessary throughput to the MD3000i, you should realize performance benefits similar to Fibre Channel.

NO FAULT STORAGE

From a fault-tolerance perspective, the dual active/active controllers and power supplies passed all our failover tests. Using the built-in alerting and SNMP capabilities, we trapped fault conditions up to a third-party SNMP reporting tool. Within seconds, e-mails alerted us that an iSCSI interface and power supply had failed.

Our test unit also came with SnapShot Virtual Disk and Virtual-Disk Copy, premium features available at additional cost. With SnapShot Virtual Disk, administrators can take a differential, point-in-time image of a volume for quick recovery of any files that have changed since the last snap.

Virtual-Disk Copy takes a complete point-in-time replica of an entire volume for fault tolerance and online backup purposes. Using a VDC image as the source volume for your tape backup is a great way to minimize the time and resources needed to perform large-scale backups.

Overall, we were pleased with the premium capabilities, but some minor features were missing. Specifically, you can create only four Snapshots per Virtual Disk in the current version. Dell's competitors are way ahead on this score. Ideally, we want to maintain five or even 10 snapshots of a file system for quick restore of user data over the course of a couple of weeks, but this capability isn't available on a per-volume basis. Additionally, SnapShots must be scripted via the CLI if you want to run them on a scheduled basis. We'd like to see a way to configure scheduled SnapShots via the GUI.

The first generation of the MD3000i has some additional drawbacks. For instance, it doesn't yet support Solaris or lower-cost SATA drives. Dell says SATA support is coming.

Our MD3000i evaluation unit included 15 SAS drives in a 3U chassis plus dual active/active RAID controllers and dual power supplies. Each RAID controller included two individual gigabit iSCSI interfaces for connection to the SAN fabric, and separate NICs provide for management. At maximum capacity, the MD3000i can serve as many as 16 hosts and support up to 18 Tbytes of data across 45 drives.

The first release of the 3000i supports RAID levels 0, 1, 5 and 10. RAID 6 will be available in 2008. Initial operating systems supported include the 32- and 64-bit versions of Windows 2003 Server, along with Red Hat Enterprise Linux version 4.0 and SUSE Linux Enterprise Server 9. Dell says it will support VMware ESX 3.1 and Windows 2008 server in the near future, though it wouldn't say when.

When it comes to features, the MD3000i isn't out to leapfrog the competition. However, its price and product support, including RIS, are above average. If you're in the market for an iSCSI SAN, this should be on your short list.

Randy George is a senior systems/network analyst for the Boston Red Sox. Write to him at rgeorge@nwc.com.