Not sure how honest these calculations are because I couldn't repeat them and the article gives no REAL detail.
Cheapest matching configuration I could find at SoftLayer was $559 for a dual processor Xeon 5504 with 12GB RAM ("Speciality: Mass Storage"). Each 2TB drive costs an additional $60. I'm assuming the raid controllers come free if you can plug in that many drives so not adding that onto the build. Total for build with 24 drives: $1999. (Assuming a free OS, and that you don't need to upgrade the network port speed.)
24x2TB in RAID-6 gives you 45TB usable capacity (all 24 drives, madness) or 20TB usable capacity (12 drives in mirrored RAID-6 configuration, probably more sane).
45TB @ $1999/mo is ~$0.045/GB, but if more than 2 disks fail you're screwed (quite likely to happen in a 24 disk configuration!)
20TB @ $1999/mo is ~$0.1/GB, and you can stand to lose at most 4 disks (at most 2 in each of the mirrored array).
Compare with the $0.11/GB Amazon S3 is charging you to store data in the TB range (excluding data transfer costs, which are free for incoming data, which ought to be the bulk of data) and I'm not really sure I follow their argument given that maintaining this backup system is going to be a PITA and the risks don't seem worth it.
Cheapest matching configuration I could find at SoftLayer was $559 for a dual processor Xeon 5504 with 12GB RAM ("Speciality: Mass Storage"). Each 2TB drive costs an additional $60. I'm assuming the raid controllers come free if you can plug in that many drives so not adding that onto the build. Total for build with 24 drives: $1999. (Assuming a free OS, and that you don't need to upgrade the network port speed.)
24x2TB in RAID-6 gives you 45TB usable capacity (all 24 drives, madness) or 20TB usable capacity (12 drives in mirrored RAID-6 configuration, probably more sane).
45TB @ $1999/mo is ~$0.045/GB, but if more than 2 disks fail you're screwed (quite likely to happen in a 24 disk configuration!)
20TB @ $1999/mo is ~$0.1/GB, and you can stand to lose at most 4 disks (at most 2 in each of the mirrored array).
Compare with the $0.11/GB Amazon S3 is charging you to store data in the TB range (excluding data transfer costs, which are free for incoming data, which ought to be the bulk of data) and I'm not really sure I follow their argument given that maintaining this backup system is going to be a PITA and the risks don't seem worth it.