In our age of growing personal digital libraries, backing data up is quite important. I've been shopping around for a backup solution for quite a while, but everything I found to date has is disadvantages. The biggest thing about RAID storage is that it's not future-proof: you can't upgrade it one disk at a time, you have to ditch the whole thing at once, and that involves moving mountains of data around. Do you have any idea how long it takes to transfer 4TB? Ouch.
So I was looking at the neat little device called Drobo. It connects to the computer as a standard USB mass storage device, but in fact is a sparse storage array, consisting of up to 4 drives up to 2Gb each, redundant and single disk failure-tolerant. It's visible as a 2Gb disk (or a few of them if total amount of storage ends up being larger than that). Almost a miracle huh?
Well, there's nothing perfect in the world. Such "sparse storage" devices have a little problem: in order to accurately track their contents, they need to be able to tell apart the blocks that contain current data (and thus must be preserved) from the blocks that contain the data from the files that have been deleted (and may be overwritten). To do so, the device must understand the logic of the overlying filesystem. And Drobo understands FAT32 and NTFS, and, secretly, ext3. But the problem is, my OS of choice is FreeBSD with its own UFS filesystem. I searched and searched and was not able to find anything useful regarding "Drobo + FreeBSD" (or Drobo + NFS, for that matter) on the net. So I didn't have a choice but to buy a Drobo and try it all for myself...
