The Ghosts of Backup Past – The Tape Era

“The future, according to some scientists, will be exactly like the past, only far more expensive.”
-Alan Kay

[This is my second excerpt from my The Future of Backup whitepaper.]

Now that I’ve set the stage by presenting some of the fundamental problems associated with backup, let’s discuss the past, present, and future of backup. I’m going to start with the past and save the present and future for postings next week.

The past of backup was dominated by tape.  In order to understand this, it helps to understand how tape was perceived in the past.  As I discussed in the fundamental challenges entry previously, in 1990, the capacity of a single tape was approximately 50 times that of a single disk.  Perhaps even more importantly, tape was much less expensive on a per gigabyte level than disk.

It was due to these attributes that people used tape.  However, despite its popularity, tape had serious issues, which it continues to have today, but I’ll discuss that when I talk about “the ghost of backup present.”  One of the major issues with tape was the issue of “shoe-shining” (also called “sawing”) – a situation in which the tape would start and stop because it couldn’t be written to fast enough to keep it streaming.  Alignment problems was another major issue that occurred when one tape drive was used to write data and another tape drive was used to read that data.

Perhaps more importantly, tape relied upon human beings to correctly implement rotational strategies and to physically move the tapes off the premises for disaster recovery.  Human beings are good at a lot of things, but they aren’t very good at performing detailed repetitive tasks when there are a lot of other IT issues needing attention each day.

These issues, along with problems associated with the architecture of tape, caused a tremendous number of restore problems and led to the poor reputation that tape enjoys today.  This led to the creation of the D2D (Disk-to-Disk) solution.  Some of the major problems with early D2D solutions were as follow:

• The price of disk drives on a per gigabyte level were much higher than the price of tape drives.    The price differential was a significant barrier to adoption.
• D2D vendors attempted to replace a relatively simple solution consisting of a tape drive and tapes with backup software that forced the user to purchase, assemble, integrate, monitor, and manage that backup software with backup servers, networking, storage, operating systems, anti-virus, and other components.  In short, the lower operational cost promised typically wasn’t realized due to the increased staff-hours required to perform these integration-related tasks.

Stay tuned for my next posting that focuses on the present of the backup industry, specifically D2D and the cloud era.