Sysadmin Snippets — Cable Tales 1

Tangles and a kind of debugging

One of a few stories around cabling, which became my ongoing obsession much like a farmer has to worry about pipes to water troughs.

The Final Straw (Cable)

As mentioned in the Intro article, I took over as sysadmin on a VAX with about 80 serial ports out the back.

The guy before me was somewhat pushed out the door. I spent an entire Easter four day weekend sealing his fate.

This is one of those times when I really wish I had photos from the pre-digital past.

I don’t know the details, but I suspect he told my boss that we had run out of ports and needed to get a hardware upgrade on the VAX.

My boss did a quick audit of the number of people actually using the computer and it didn’t add up.

When you looked at the back of the computer, there was just a massive tangle of cables disappearing under the floor. A meter or so away, they emerged up to a big patch panel, connecting to different outlets across three floors.

Another tangle of them came up into the communications cabinet which contained a “multiplexor”. This device took a bunch of incoming serial lines and combined their signals onto a single leased phone line, talking to a similar device down at the minesite.

So my boss asked me to spend some portion of my Easter long-weekend sorting out the cables.