For those who need huge storage spaces to process, version control, and organize data, the striped DS-500 (once you get it running) is very compelling. Table 1 shows the relative read speeds of DAS and NAS across the six file sizes tested by iozone. Given the astronomically higher speeds of reading (DAS was from 6.6 to 145.8 times as fast as NAS in these comparisons) and substantially higher speeds in writing, directly attached storage should be able to carve out a significant niche for itself.
|File Size||DAS RAID0
Table 1: DAS RAID0 Divided by NAS RAID5
But, the Norco DS-500 itself is a buyer beware product. The software that comes with it is just plain bad. Using DR-DOS to flash firmware in an adapter when a Windows program could do easily do it is below the professional standards of Norco's competition and the computer industry in general circa 2007. This was OK in 1994, but it is laughable to see today. And having to change firmware in the eSATA adapter in the first place, when switching from RAID0 to RAID5 is again, cumbersome, unprofessional, and uncompetitive.
I also encountered the following problems in getting the DS-500 to work:
- The Norco install disk's directory structure when booted up under DR-DOS is not the same as than the install disk's directory structure when viewed with Windows. Very confusing.
TIP: I haven't used DOS since 1990, but in order to flash the DS-500's BIOS to run RAID5, I had to learn a new DR-DOS command. When DR-DOS dumps you to the A> prompt, you need to type D:<enter> to find the partition that has the BIOS flashing tools.
While Norco does tell you to go to the /bios directory, I could not find the instructions to go to the D: drive to find this directory. This cost me a couple hours to figure out. In the process I had to shift out of "fun to install new products and play with them mode" and into "trick the system into giving up its secrets" mode. If you hate products that make you shift out of "fun to install new products and play with them mode" the DS-500 is not for you.
- The BIOS flash utility on my evaluation card did not work. Norco sent me a second card with the RAID5 BIOS pre-installed. Given the terrible performance of RAID5 on the DS-500 (see next bullet point) Norco defaulting to the RAID0 BIOS in the adapter is understandable. Having to flash your adapter to get RAID5 is probably an important cue. If you need high performing RAID5, you are going to have to work to make it happen. And I would guess that the DS-500 will never be in the same league with a RAID5 ATA or SATA controller.
- Norco's instructions for setting up RAID arrays with the DS-500 are not good enough for newbies. The word that comes to mind for the instructions is "disjointed." That is, the DS-500 manual is long on pointers and short on the step-by-steps many home users need to make a RAID system productive. I've learned from the many back-channel thank-you letters from the DIY RAID5 article, that step-by-step instructions are indispensable for people seeking to set up RAID5.
- The adapter Card Number (4618) and the product number referred to by the driver (3124) are not the same. This is needlessly confusing.
Once you get through the painful installation process, the DS-500's DAS RAID 0 performance gives us small net builders something to think about. Where should we directly attach and where should we network attach our storage? If we're editing movies we'll definitely want DAS. If we're just watching them over the LAN, then NAS is probably fine.
For example, I have a friend who bought a 2 TB RAID 5 NAS to organize thousands of digital images captured in the course of his business. Before the NAS, my friend had 30 linear feet of CDs with the images burned on them and a fleet of 5 GB, 10 GB, 20 GB, 40 GB, 80 GB, 120 GB, and 250 GB ATA hard drives that he was constantly swapping into and out of 4 firewire external enclosures. For my friend, the 2 TB of space were necessary to have the degrees of freedom to organize his digital images.
After he got his system up and running, however, he complained, "This is just too slow to work on." When I asked him why he thought so, he said that a 1 GB image in Photoshop takes "forever" to open. I have observed that many people like my friend buy NASes and then be disappointed with their slow speed.
So when you need fast opening, fast saving, huge spaces to work in, direct attached is the way to go. When you need huge spaces and care more about access from anywhere than speed, NAS is the way to go.