NAS Revisited: The Infrant Alternative

As I indicated in a blog post three weeks ago, at the tail-end of a review of Buffalo Technologies' TeraStation, I also planned to test-drive Infrant Technologies' ReadyNAS products. And one week later, test-drive it I did. That it's taken me two more weeks to tackle this writeup is a function of two impinging factors; time spent waiting for feedback from Infrant on issues I uncovered, and the need to also deal with other work responsibilities (including two business trips). So, sorry And here we go….

Instead of re-hashing points that other reviewers have already ably addressed, I'll first point you at three other solid writeups:

• The Tom's Networking review, published in mid-August, that I previously mentioned in my September 8 blog entry,
• Some coverage at ExtremeTech, published in late May, and
• A writeup at Ars Technica, published a bit over a week ago.

Two aspects of ReadyNAS particularly motivated me to tackle this study. First off, ReadyNAS hardware-accelerates the calculation of XOR parity information, such as that used in RAID levels 2-7. Conversely, XOR generation is fully software-implemented in the TeraStation, running on its PowerPC processor. Also, whereas the TeraStation employs PATA-100 drives with 2 MByte buffers, the ReadyNAS uses SATA-150 drives with 8 MByte buffers. Do these ReadyNAS conceptual advantages lead to tangible performance improvements? Let's find out.

Infrant's ReadyNAS product portfolio (which also covers chip and production-ready board OEM building blocks, as well as 1U chassis versions) consists of two similar, but not identical, families. ReadyNAS 600 products, like the TeraStation, come in four-drive combinations with 1 TByte (four 250 GByte HDD) and 1.6 TBytes (four 400 GByte HDD) worth of cumulative maximum capacity, and in user-defineable RAID 0, RAID 1 and RAID 5 configurations. As I'm writing this review, Amazon has the 1 TByte ReadyNAS 600 priced at $1299 and the 1.6 TByte ReadyNAS 600 is listed at $1899; both products are more expensive than their 1 TByte and 1.6 TByte TeraStation competitors, and there's no 0.6 TByte ReadyNAS 600 offered. Infrant's website lists other online and distribution sources.

The ReadyNAS X6 family is the more unconventional, and more technically interesting, product line, addressing both consumers' desires for a low entry price point and for easy configuration, expansion (conceptual analogies between what I'm about to describe and the SLI or CrossFire dual graphics card concept I wrote about two weeks back are apt) and reconfiguration. You can buy it in a drive-less variant (currently $599 at Amazon); unlike the TeraStation, the ReadyNAS stores its boot code in a dedicated semiconductor memory device. With one drive inside, the ReadyNAS acts as a conventional RAID-less NAS. Plug in a second drive and Infrant's proprietary X-RAID software transforms the NAS into a RAID 1 array, with the same capacity as before but offering HDD crash-surviving data redundancy.

Add a third drive and the total NAS capacity doubles; the ReadyNAS auto-transforms into a RAID 5-like setup, however in the words of Infrant's PR guru, Sam Feng, "without destroying all existing data" as would be necessary if Infrant was implementing true RAID 5. In the background, the ReadyNAS formats the new drive (an approximately 2 hour process), you're then prompted to reboot and the volume expands (~30 minutes, during which the drive is inaccessible). Again quoting Sam, "after the expansion, the new volume will become accessible while the RAID is fully re-synced in the background. During this RAID re-sync process, the performance of the device will be much slower than normal.After the 2-3 hour re-sync process, performance will return to 100%."

Install a HDD in the fourth drive bay and the process repeats; you end up with additional cumulative capacity reflective of the size of the added drive (all four drives must be identically sized). I was able to confirm for myself that the ReadyNAS X6 works as advertised; the system Infrant sent me had two of its four drives' SATA cables disconnected. I first booted and fully configured the system in a two-drive arrangement, then incrementally plugged in each of the two other drives and observed the total capacity growth without corruption of files previously stored to the NAS. Pretty slick! If I were to buy a ReadyNAS X6, I'd probably go for the HDD-less unit and incrementally (rebates, after all, are usually limited to unit, one customer, one address, etc…) build up a four-drive configuration via special deals at DealNews and Techbargains.

Continued with 'NAS Revisited: More On ReadyNAS'….