Friday, May 29, 2009

Faulty Tape Drive

The tape drive on a server at work went belly up yesterday. I hoped that it was something simple that I could fix, but alas, it was not.

The subject tape drive is a Compaq DLT 40/80 drive that uses DLT3 tapes and can hold up to 80Gb compressed. We use this tape drive to back up the data and applications on our old minicomputer, a DEC AlphaServer 2000 which runs HP's OpenVMS. DLT drives are great ... obviously when they work ... and this technology lead to better drives like the Ultrium. DLT stands for "Digital Linear Tape" because the data is written to the tape linearly, in long horizontal stripes like an 8-track tape, rather than in slanted stripes like a VCR tape. This slanted stripe technology is used in DDS and AIT drives and did, indeed, come from the technology used in VCRs, so called "helical scan".

The problem was that this drive got a tape stuck inside for no apparent reason and was making buzzing noises. We had seen this problem before when using tapes that had been used previously with a different style of tape drive. DLT 'VS' drives and DLT drives take the same tapes, but cannot be used interchangeably. Once a DLT tape is written to using a 'VS'-style drive, it is then rendered unreadable by a plain DLT drive. If a DLT 'VS' tape is inserted into a DLT drive, it tries to find the alignment tracks by moving the heads. This is where the buzzing comes from.

The tape that was in the drive had been used previously on this same server, so why it was doing this was a mystery. Powering off the tape drive, resetting it, etc, did not work and the tape would not eject. I removed it from its enclosure to get the tape out manually, hoping that I can reassemble it, runa cleaning tape a few times and all will be well.

There was no such luck.

I cut the tape and got the cartridge out and removed the tape from the internal spool and got the tape drives leader put back on the hook. On this tape drive the "flashing lights" error usually indicates that the leader, a thin piece of plastic attached to the internal spool that hooks onto the tape inside the cartidge and pulls it into the drive, is unhooked from the little plastic hook that holds it in place to be able to catch the tape when the tape is inserted.

I plugged the tape drive back in to its enclosure, powered it up and reset it. I loaded up a cleaning tape to test it out and maybe clean it up so it might work once again.

Again, no such luck.

I kept trying to eject the tape, and the more I pressed eject the more tape would be wound into the drive! Within a few minutes, the drive had taken so much tape into its internal spool that it completely emptied the cleaning tape! For those that might not know, DLT tapes and many of their kin to not have the end of the tape permanently attached to the spool within the tape cartridge. Thus, the tape could come completely out of the cartridge ... and it did.

Fig. 1: 'Manually' unwinding the tape.

So, to clean up my mess, I again removed the drive from its enclosure and connections and got the cartridge out of the drive. I began to pull the tape off the spool when I got the idea of making it easier on myself by letting a power screwdriver unspool the tape for me! I tucked the loose end of the tape into the bit holder and put the screwdriver bit back in to hold it in place then started winding. My workmate CB told me that I should have thought harder about it and use a piece of tape to hold down the button so I wouldn't have to hold it. Great idea!

I got the tape removed and again reattached the leader to the hook and put everything back. It was a lost cause, but pretty amusing to work on. Thankfully our service agency we contract with had all kinds of interesting old equipment, including tape drives like this, so getting a replacement will be quick and painless.

Tuesday, May 26, 2009

O, Canada

I went to Canada over the weekend! I went, specifically, to attend Anime North 2009 and to visit with "Piper" and "Psyche".

This was the first time that I had ever been to Canada. Upon arriving at the border for the immigration checkpoint, the agent was surprised ... well, shocked, really ... that me being as old as I am and living in Ohio had never been to Canada.

The trip up and back was rather uneventful, other than the ubiquitous construction. Driving through Michigan was an awful chore, numerous construction zones, potholes on the interstate that could swallow a car. The roads in Canada, however, were nicely maintained.

Driving through Canada was no different than in the US. Highways worked the same, signs were similar enough, drivers were no different than I experience in Ohio.

The weather was great throughout the whole weekend. I drove much of the way with the windows down when the temperature wasn't oppressively hot. Upon entering Michigan, I noticed a peculiar odor of sewage that persisted until the Ambassador Bridge. I don't know what that was all about, but it was nasty.

Before I left, I washed my car. When I got home, it looked as if I had driven through a plague of locusts! The windshield is splotched with the remains of bugs like I've never seen. The front bumper is even worse. I guess I will have to wash it again!

The trip was a little over 912 miles (or, nearly 1 kilomile in metric) there and back. It took about 8 hours one-way straight driving. Surprisingly I averaged 25.4 miles per gallon on the entire trip. That's pretty good for a car with a V8 engine. I usually average 17.1 mpg in daily driving. Of course, daily driving is a stop-and-go affair. It also proves how nicely the 'Active Fuel Management' of my engine works. When cruising at highway speeds, it only uses four of the eight cylinders to save fuel.

Fig. 1: The view from my hotel room.

I stayed at the Toronto Airport Marriott which was a very nice hotel. The bed was probably the most comfortable bed I had ever slept in. The hotel was very clean. I did have trouble with the pay-to-use internet service. I had to jerry-rig the settings on my laptop to get it to work, but it was speedy and served me well. The television service was being worked on while I was there, and some stations were absent or had lots of interference. Other than that, the room was great and I would definitely stay there again.

Something, though, caused me to break out on my hands and face. I speculate that it was some kind of fabric softener on the sheets and pillow cases. However, one of the medications that I am on does have the side-effect of sensitivity to sunlight, so that could be it as well.

Some random observations:
  • Michigan smells bad.
  • Michigan roads suck.
  • Michigan drivers suck.
  • Everything in Canada is metric. Speeds, lengths, people. Everything.
  • Not all Canadians say 'Eh?' or 'Aboot'.
  • Nearly all signs are in English and French.
  • 'Reduced Speed' is translated as 'Reduit Vitesse'. It just sounds cool.
  • Canadians drive on the right side of the road.
  • Milk in Canada comes in bags.
  • Canadians look like regular people.
  • Trips are shorter in Canada because they use kilometers.
  • Canadian money is in colour, and the $5 has an image of people playing hockey on the back!
I will be posting an entry on my blog account on LiveJournal about my experiences at Anime North 09, meeting my terrific Canadian friends and observations of the people at the convention. I'll post a link here to that when I get it written, so stay tuned!

Anyone from the US that may be thinking about going to Canada just to check it out, I highly recommend it. Be sure, though, that you are aware that starting June 1 border crossings by land and sea will require a passport or passport card. Birth Certificates and other proof-of-citizenship documents will no longer be accepted. Travel by air will continue to require a passport book, with no exceptions.