Bests & Worsts Reviews from Amazon

What is Amazon Vine and why do these reviewers write so much stuff without saying anything? This review is for people who want to know only one thing: Does this device actually survive a disk failure? The answer is Yes. My sister recently lost 2 of her external USB hard drives. She had to pay $3000 to a data recovery company to retrieve her data. I figure that $400 for a Netgear ReadyNAS Duo is small change, if it actually did what it claimed to do, which is survive a disk crash. The only way to know was to test it out. I have about 40 GB worth of MP3 files stored on my Linux server, accessible to my Windows laptop using Samba as a network shared folder. From my Windows laptop, I started copying the MP3 files into the \media share folder on the Duo. Over gigabit ethernet, I estimated a transfer speed of about 15-20 MB/second. More than I expected, considering the weak processing power of the embedded Linux computer on the Duo, and because there are 2 concurrent network copies going on, from Linux to Windows, then from Windows to Netgear. Gigabit ethernet is awesome. While the copy was in progress, I inserted a second 750 GB hard disk (a Seagate Barracuda 7200.11 series if you are curious; my Duo came with one 500 GB Seagate Barracuda 7200.11 installed) into the second slot. The Netgear recognized it and started to incorporate it into the RAID system in 2 steps: first, format the drive (an ext3 Linux filesystem I think), took about 2.5 hours; second, synchronize the data from the first disk to the second disk, took another 2.5 hours. During this time, the 40 GB MP3 file transfer continued without a hitch. Next, I configured the Duo to enable NFS (Network File System) and mounted the /media folder onto my Linux box. Now I had access to both the original and the copy on the Duo. I ran a "diff -r" command to do a recursive binary diff between the two directories. Came out perfect, no file corruptions. I went back to my Windows laptop, and started another 40 GB copy of my MP3 files to the Duo. While the write was in progress, I _removed_ the 500 GB disk. The Duo detected a disk failure within a few seconds, and sent off a notification email to my GMail account, warning me of a disk failure. You can configure the notification email address to send the message to, say, your SMS on your mobile phone. As before, the MP3 copy to the Duo continued without a burp. I then inserted a second 750 GB drive into the first slot, while the copying was still in progress. The Duo formatted and synchronized the new disk, and after about 5-6 hours, I once again had a fully redundant RAID system. Did another 'diff -r' just to make sure the data was not corrupted. None found. When upgrading from a single 500 GB to dual 750 GB disks, the proprietary Netgear X-RAID filesystem makes the process as painless as possible. After both disks are formatted and synchronized, all you need to do is click on a button in the admin web interface (don't remmeber the exact wording, something like "Expand Volume") to take advantage of the bigger disks. In conclusion, I tested the Netgear Duo through a simulated hard disk crash and hot-swapping disk upgrade, and found that it performed perfectly, did not corrupt the files which were being written to it during the process. The Duo performs reasonably well (15-20 MB/sec write speed over gigabit ethernet) and costs only about $400, far cheaper than what you'd pay to recover your data after your disk crashes. It has an impressive list of other useful features (USB backup, USB printer, NFS, Rsync, FTP, Bittorrent, etc) that you can read about in other reviews. The most important question for me was, will it survive a disk crash? I won't know for sure until a disk really does crash, but based on my testing, I think the answer is Yes.