Exclusive: Dell and EMC ease SAN assembly requirements

Not long ago, the very idea of setting up a SAN in a small datacenter would have triggered eye rolls and contemptuous comments. SANs were reserved for companies with pockets deep enough to buy millions of dollars’ worth of equipment and to hire top-notch engineers.

Things have changed. New technologies such as iSCSI and SATA, combined with vendors’ need to open new markets, have resulted in more affordable SAN products that more closely meet the budgets and the technical capabilities of small datacenters.

In June, Dell began shipping one such entry-level SAN: the AX100. Born through cooperation with EMC, the AX100 is very competitively priced and promises mature FC (Fibre Channel) connectivity with exceptional ease of use, simplified setup, and the flexibility to adjust to different deployment scenarios.

My AX100 package had all the components to build a small SAN, including the storage array, an FC switch, two FC HBAs, and a UPS module. All that equipment suggests an intimidating setup, but the components of the AX100 package are engineered to be user friendly.

In fact, the package includes a simplified version of Navisphere, EMC’s leading management application, and some utilities that use auto-discovery to automate the most critical configuration steps, such as setting IP addresses and registering your servers with the storage array.

Furthermore, the installation is driven by an easy-to-follow template that turns a pile of boxes into a ready-to-work SAN in 10 easy steps. Appropriately, Dell says, “It’s a SAN in can.”

Hardware Breakdown

The system’s 2U, 2-feet-deep, rack-mountable enclosure is the heart of the unit. It hosts two SPs (storage processors), two CPUs, 1GB of memory, two redundant power supplies, and seven cooling fans spread between CPUs and disks. On the outside, the SP assembly mounts two copper ports to connect your LAN, and four optical ports for redundant connectivity of its two SPs to host computers or to the fabric.

An additional RJ45 port connects the rack-mounted APC Smart UPS unit, which, in case of a blackout, ensures a controlled shutdown and preserves the cache content.

The front of the AX100 mounts as many as 14 SATA drives with 160GB or 250GB, capacity. If you need to scale more, look elsewhere. Mine shipped with eight large drives, which gave me slightly less than 2TB.

The included 8-port Brocade SilkWorm 3250 ships with a wizard that makes configuring the FC switches easy enough for a rookie admin. Connecting four servers and the AX100 to the SilkWorm was a snap and didn’t require setting zones, because the switch came preconfigured. I simply followed the instructions, connecting the array to the first two ports and each server to one of the remaining switch ports.

Smart Software

With my SAN pieces all connected, I moved to setting network parameters and creating a user account on the AX100. The Navisphere Initialization Utility, a wizard from EMC, automatically found the AX100 on my LAN and proposed screens to change the IP address and create an administrative account. In seconds, I was done.

To make the AX100 aware of all my servers, I ran another small application from EMC on each machine. Next, I pointed the browser to the array, opened Navisphere Express, and saw those machines correctly registered with the array.

With my setup complete, I was now ready to create new LUNs (logical unit numbers) and assign them to my servers. From this point on, Navisphere Express was just about the only administrative tool I needed. The exception was EMC PowerPath, a separate application managed via a GUI similar to that of Microsoft Management Console. PowerPath makes server connections to the SAN faster and more reliable.

Through Navisphere, I created two disk pools out of seven physical disks, leaving one spare for contingency. Still in Navisphere, I carved a LUN from each disk pool, assigning both to my server.

The process went smoothly. If you’ve tried older versions of the software, forget that experience. Navisphere Express is a pleasure to use: friendlier, faster, and capable of handling all the storage management you’ll ever need, including creating volume snapshots.

Back at my server, I launched Iometer with a disproportionate number of outstanding I/Os on the two volumes, then opened the PowerPath admin: The nearly 2,000 IOPS (input/output operations per second) created by Iometer and the numerous I/Os waiting in the queue were almost evenly split across the two HBAs.

To test the fail-over feature of PowerPath, I pulled the wire from one HBA. At my console, I saw the surviving connection absorb the entire load while Iometer still ran at full speed.

Leaving Iometer running, I pulled one drive from the AX100 to simulate a fault. Navisphere reported the status of that drive change as Failed. In less than 20 minutes, my spare had replaced the failed drive, but replacing fuller drives can take longer.

Interestingly, when a fault is detected, the AX100 will automatically turn off write caching until the problem is fixed, another example of its built-in user friendliness.

The AX100 package leaves little to be desired for a small company moving to networked storage. Perhaps the most comprehensive, affordable, and easy-to-order entry-level SAN, it does not skimp on performance or reliability, and Dell has removed most of the thorns from installation and management. If you are ready to jump on a SAN, land on the AX100.