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Of rats' nests and fans
Mar. 23rd, 2009 08:26 pmI decided to activate the new server by moving devices around in virtual space rather than by moving patch cords around in real space. In order to do that, though, I needed a map of the preset state of our switches and patch panel. No, there never was such a map. I've been lamenting that for years, but the previous network management team never made one even though they were being paid an outrageous amount (more than I make, on an hourly basis, by far.)
Doing such a chart, which is really just a spreadsheet affair, requires standing at the patch panels and tracing individual cables through the rat's nest to find out which panel jack is connected to each port on each switch. We have only about 150 ports, but the patch cables are routed very "imaginatively" and about 95% of them are the same color. None are tagged in any way. This took a couple of hours.
I happened to glance down at the server itself, since it's now in the same communications rack, and saw a flashing amber light. This didn't seem right. On the back there was a bright red flashing light. No label on either, but I went to look up the documentation on Dell's web site. There's a laundry list of possible causes, but a fan failure is right at the top. OK, I was warned that fans tend to conk out (it has four of them) and even received a bag o' fans to be used as replacements. I've not worked with rack-mounted servers of this sort before, and I have to say it's pretty slick. No interruption in service, no need to kill the power. The encapsulated fans can be replaced while the server is running. Just flip open the top, find the fan with a flashing red light next to its power connector (the others are all steady green,) unplug it and slide it out. Slide in replacement, plug it onto the power posts, the flashing red light turns green, and you can button up the case. Not even a screwdriver is needed. Worked like a charm.
Doing such a chart, which is really just a spreadsheet affair, requires standing at the patch panels and tracing individual cables through the rat's nest to find out which panel jack is connected to each port on each switch. We have only about 150 ports, but the patch cables are routed very "imaginatively" and about 95% of them are the same color. None are tagged in any way. This took a couple of hours.
I happened to glance down at the server itself, since it's now in the same communications rack, and saw a flashing amber light. This didn't seem right. On the back there was a bright red flashing light. No label on either, but I went to look up the documentation on Dell's web site. There's a laundry list of possible causes, but a fan failure is right at the top. OK, I was warned that fans tend to conk out (it has four of them) and even received a bag o' fans to be used as replacements. I've not worked with rack-mounted servers of this sort before, and I have to say it's pretty slick. No interruption in service, no need to kill the power. The encapsulated fans can be replaced while the server is running. Just flip open the top, find the fan with a flashing red light next to its power connector (the others are all steady green,) unplug it and slide it out. Slide in replacement, plug it onto the power posts, the flashing red light turns green, and you can button up the case. Not even a screwdriver is needed. Worked like a charm.
