Two year ago, I got a Drobo Pro eight bay and it has been working OK right up to a power outage (I should have had a UPS) that caused the SCSI controller to fail. Got a warranty replacement from Drobo (thanks Drobo!), but realized I needed more backup as having all your files on a NAS is nice, but it is hard to get a backup for an 8TB array (I use crashplan for off-site backup and dance around Comcast's 250GB/month limitations).
So what to do? Well, I have been using 3 old 1TB Time Capsules for casual backup, but the math shows it is pretty hard to make that work when you have 3.7TB used on the 8TB array (its running Drobo's proprietary soft RAID, so there is actually 13TB of real storage). The answer is of course you need a primary and a backup NAS, so what to get?
Someone mentioned to me from the blog that I should try the EMC box, but in searching on the web, there are so many other alternatives. One that won both PC Magazine winning editors choice in Feb 2011 and CNet reviews (winning January 2011 editor's choice) is the Synology DS1511+. It is $800 street from overstock.com without disks. Now that this is done, how to fill it, well with the new 3TB drives, that's the logical choice and xbitlabs just did a shoot out. What this means is that my 8TB system has a maximum of 2TB drives, so now I can do the same with just five bays instead of eight. StorageReview ilked the Caviar Green as it is low power and big capacity. The Caviar Green is a 5200 rpm drive so a bit slower.. The Hitachi and the Seagate XT are of course 7200rpm and faster but use more power. In the end, the Seagate looks pretty good. In studying the newegg.com reviews of the Hitachi and the Seagate, looks like both have significant reliability issues as the WD is slow, so no obvious choices although it is amazing how cheap these drives are at$150 for a 5 year warranty from Seagate for instance.
Also, I have to figure out how to set it up, but both the Drobo Pro and this Synology box support iSCSI which means I can configure my gigabit switch to directly connect say my iMac for video via Ethernet. Of course, there aren't any iSCSI initiators that work right now on Mac OS X Lion, so I'll have to settle for Firewire and direct connect for now, but iSCSI means I could potentially remote this in the basement.
The main issue looks like Lion compatibility. the Synology uses an old version of AFS Server (called netatalk) which is slow and not compatible. They have a new version of their operating system that uses the later version 2.2.