Friday, August 12, 2011


Many years and a couple of jobs ago, I twice got on a plane to a customer site, there to help them recover from a corrupted file system. In both cases, the unit that failed was a 25 megabyte disk. Now, Apple will sell you an iPod with 16 gigabytes of storage, nearly 700 times as much as fit on these units. The iPod will fit nicely in a pocket, but these units came in a cabinet about 2 feet wide by three feet deep by a foot and a half high. The prudent user backed them up, generally using 8 inch floppy disks that held 1.2 megabytes. The main drive (and I suppose the floppy--I never looked) was driven by a rubber belt like a car's fan belt--if it dropped off the system would halt.

Recovering from file system corruption required backing all recoverable files off to the floppies, a few dozen at a time. This made for a long day and a late night, and one never got all the data back. At one of the sites, I sat in on the inquest where a manager a couple of levels up, with perfect southern manners, made it clear how inappropriate such disruptions were; I met some volatile and expressive customers at that job, and at least one who was outstanding at profanity, but there was none I'd fear more to disappoint than the lady with perfect manners.

The other week I found myself the customer in need of help. An old computer crashed, and damaged a couple of file systems beyond recovery. Pretty much everything I needed was backed up, but the backup and restore software depended on a number of settings that had changed between the old operating system and the new one I had restored. After co-workers were unable to help me, I put in a call to the vendor's support line, where I was promised a call back within two hours. The first cogent response came 21 hours after my call, by which time I had figured out a way around the difficulties.

I have seen disks develop from the 25 megabyte units to 1 terabyte disks (400 thousand times larger, that is). I have seen the backup media go from 8 inch floppy and 1 inch tape to 4 mm tape, to DLT  through a couple of generations of LTO. The throughput rates and capacity have astonished me at each jump. Yet it seems that you can never get data back as quickly as you'd care to . You can get gigabytes and soon terabytes back as fast as once you could megabytes. But now it's GB and TB you need back, not MB.

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