Unix Backup and Recovery

Which Backup Utility Should I Use?

Before examining how to perform Informix backups, we need to understand the various backup options that are available to an Informix DBA. There are three backup utilities available with Informix: onbar, onarchive, and ontape.

A Quick History of onarchive, onbar, and ontape

Around 1993 and 1994, very large Informix databases started to appear. (Back then, “large” meant anything greater than 100 GB.) The only utility that Informix customers had was ontape . ontape’s one big flaw is that it is single-threaded. How do you back up 100 GB to a single device, especially when the devices available could back up only at rates ranging from 500 KB/s to 3 MB/s? Informix customers started screaming for a multithreaded backup system. (I was one of them.)

Informix, in an attempt to meet these demands, purchased the rights to a third-party program that became known as onarchive . Its syntax was arcane, complex, and completely unlike any other command on Unix. (It wasn’t as complex as sendmail, but it was close!) The forward-slash method of passing options to a command seemed bizarre to most Unix system administrators, and it came with a manual that is almost the size of this book.

I was there

By the time in my career that I met onarchive, I had learned dozens of products just by browsing the manuals. I read the onarchive manual cover to cover four times and attended the Informix onarchive class. I was still confused. The most disconcerting part of the class was how ...