No, they aren't going Google's route!

Google's operation has at most half the disks-per-rack density of Backblaze, but with 4 or 8 times the server density. Google does almost all their computation on the same nodes where the data is stored. Google is also storing each tablet a minimum of 3 times within each cluster, with most systems having multiple replica clusters.

Backblaze's system is going to have several orders of magnitude less bandwidth:

  way too many drives in one server (some of them on the PCI bus!)
  use of port multipliers (causing 5 drives to share one SATA cable's 300MB/s)
  RAID6 with too many drives per array (15-way XOR is no fun)
  why use JFS?
  only access is via HTTPS, not clear if SSL is done on the pod

I'm guessing that backups are accessed rather infrequently and that someone recovering their data won't mind a few seconds in lag time. This isn't my area of expertise, but their trade off seems sensible. It's just a different scenario than what google is dealing with.