I started by installing FreeNAS (0.69b2) onto a 1 GB Kingston Flash drive, first using the onboard Ethernet just to get going. But after trying both the released and most current (0.7.3514) builds without success, I gave up and retrieved an Intel PRO/1000 MT gigabit PCI NIC from another system. That installed without a problem and I was up and running.
The next hurdle was to get a RAID array configured so that I could start iozone runs. I'm not a 'nix (or FreeBSD) jock and am accustomed to the simple RAID configuration controls on consumer NASes. So I found the FreeNAS controls to be less than intuitive.
After about an hour of failing to successfully create a RAID array, I finally resorted to downloading the PDF User manual and found what I needed in Section 4.6 (Software RAID configuration with geom modules).
As the manual describes, the basic steps for configuring a simple RAID array in FreeNAS are:
1. Add Disks
2. Format Disks for Software RAID
3. Create the RAID array using the previously formatted for Software RAID
4. Format the newly created RAID array in UFS filesystem
5. Add Mount Point
6. Enable Services (CIFS, FTP, etc.)
After reading this (and the additional details of each step), I quickly discovered that I was skipping Step 4. Once I stopped doing that, my array was up and I was able to start testing. All testing was done with the "New NAS Test Bed" machine (Core 2 Duo E4400, 512 MB, Win XP SP2) that I'm using for the Fast NAS series.
The first write results are shown in Figure 4 and include RAID 1 test results for a D-Link DNS-321 (run on my standard iozone test machine - 2.4 GHz P4, 512 MB, Win XP SP2).
Figure 4: Atom Write performance - FreeNAS
I expanded the Y axis to show the subtle difference in the non-cached section of the plots, so the 66.9 Mbps measured gigabit transfer rate reference line is not shown. This is fine, since none of the results come anywhere near it. Note that the DNS-321 is the winner, in RAID 1 no less, with a steady 15 MB/s after its rather meager 64 MB cache is exhausted.
The read results in Figure 5, however, are a different story. The DNS-321 is left in the dust in the low teens while even the Atom's RAID 1 reads stay above 30 MB/s until the test file size equals the Atom's 2 GB RAM size.
Figure 5: Atom Read performance - FreeNAS
While these results were decent, they came nowhere near the PCI gigabit Ethernet transfer limit or 67 Mb/s SATA drive "wall" that I saw in my testing on the Core 2 Duo based "BigNAS" testbed. Is that really all that the Atom has to offer as an inexpensive NAS platform?