GNU Testimonials—Robert E. A. Harvey

From: Robert E. A. Harvey

I work on research ships, mainly deep seismic acquisition, but other types as well. The story I am about to tell is of a single piece of GNU software. Tar. For many years we have been using systems with disk stacks containing disks no more than 3 Gb in size, and the application code has facilities to span data across disks. But for backup, it calls a shell script which calls tar. And does so on a disk-by-disk basis. We have been taring to Exabyte 2500 drives, and fortunately no one disk was bigger than would fit on a tar tape.

The world changes, and things move on. Because of a monster project last year I was forced to replace several of the disks in the stack with 180Gb ones. The application code coped, but the backup needed very careful human intervention instead of using the facilities from the application—because now it was easy to launch a backup that would not fit on one tape.

The solution? GNU tar. GNU tar has allowed us to do two things in one go: to split backups across more than one tape, and to connect directly to an IBM 3590 tape drive on another workstation for larger capacity. This was made possible, too, by the well-written application code whose GUI merely calls a shell script, and by some of the basic modularity of Unix. But without GNU tar it could not have been done. A two kilo-euro investment in software, hardware, training, and installtion on the vessel has been rescued from obselescence by me—with some help from GNU tar.

GNU tar is an enhanced version of standard Unix tar. But the enhancements are sensible, and merely looking at the help output one can see that they have been made by practical, experienced, people working with the code they write. The code is solid, reliable, and achieves exactly what it sets out to do. And it is familiar enough that anyone can use it.

How long did it take me to make this astonishing change? Twenty hours to download some binary packages to the vessel. And around 3 minutes to install them. Another hour for the changes to the application script, and 6 hours to test. (Have you ever tried writing 8.6GB of data?).

I have been using GNU, and GNU/Linux, software for many years: since my days at Rockwell Automation at least, call that 1984. I just thought it was time to say thank you to the originators of some of the most useful bits of code on the planet.