Monday, September 08, 2014

Mighty Red Face Here at NAS Central

One of the reasons I give to people for outsourcing their work, for example getting us to rip their CDs rather than do it themselves, is that we make the mistakes first - so you don't have to. Indeed I may well have said that to the client who has asked us to spread the musical love across his three properties, each of which has a NAS drive. His simple requirement is for a copy of his music to be placed onto a hard drive, then copied across to other drives, which will be installed inside the NAS box in each location.

We've had some problems with this. Initially we'd been given some Seagate drives to use but after much trial and far too many errors we established that the drives, whilst OK to use inside a PC or a free-standing USB enclosure, simply weren't up to the task of running trouble-free in the NAS enclosures he's bought. After much toing-and-froing we now have a collection of Western Digital Red drives, tailor made for a NAS. Very good they are too. We're in the process of copying 1.5 TB data from one of our PCs across the LAN to the NAS.

On Saturday evening I was talking to a friend who manages a major international network for a financial services company. We talked about what I was doing and I mentioned this project, which for us is rather unusual, for him rather routine. I told him how long each transfer is taking and ran through a list of the kit we're using - mainly variations on gigabit ethernet. He thought for a few moments then said it shouldn't be taking anywhere near as long as that. Doing some mental arithmetic out loud he thought it should take around half the time the first transfer had taken.

Why?

"Have you got your wires crossed?" he asked. I didn't think that possible but first thing this morning, before we started on disc 2, I was checking cables and connections. The router plugs were all present and correct as were the plugs into the NAS and the PC into which the USB hard drive with the source files was plugged. I even made sure that USB 3 interface was functioning OK, which it was. The only thing left to check was the quality of the cables. All looked fine and blue, no sign of mousey rodent attention, and the two key cables ran neatly under a mat. Two one side, two coming out the other. For some reason I thought it best to lift the mat and see what was underneath. To my amazement the wires were (physically) crossed, and the effect of the odd footfall on the mat was that at the crossover point the cables were compressed. I took a close look and they both looked fine and undamaged but when I put them and the mat back I made sure neither ran over the other.

When I started the data transfer I didn't think it would make any difference, but something has punched the go-faster button. Just as my friend predicted, data transfer seems to be running twice as fast as it did first time across. So if you have any data wires running anywhere in your home or office, just check that transfer rates aren't being artificially choked by a crossed line or two.

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