While getting our new tape jukebox working, I was running into all sorts of seemingly random and odd behaviors. The new jukebox (run by WinCE) couldn't consistenty recognize all of it's drives. On boot, the server did not always find all of the devices connected. Tapes would show up as unreadable in some drives some of the time. General oddness all around.
I checked the cabling, the scsi id's, and the termination. Everything was as it should be. I even added up the various lengths of cable to make sure I was within spec for total cable length. Through a tedious process of elimination, I was left with a seemingly bad cable. Which lead me to sysadmins Law 7;
Sitting in our server room right now is a new 250 lb toy. I spent a few minutes this afternoon contemplating how exactly we were going tolift that thing onto the rails (it doesn't help that I'm not particularly confident that the provided sliding rails will work as advertised).
I brought this problem up to a friend who works in a large datacenter. He told me of the existance of lifts built to ease the process of hefting large servers into a rack. The only such lift that I could find advertised for sale is one from Server Life Corporation (which seems to cost about $8k). IBM makes reference to a support document pdf doc. Not quite designed for racking servers, but R on I's Lift-o-flex line looks to be a reasonable compromise of function to cost (under $1000 for the largest ones).
Not having a large enough serverroom to justify even the Lift-O-Flex (and certainly not being patient enough to attempt to acquire one before using the new toy), I recruited a couple of burly co-workers and it was heaved 10 inches up and two feet back onto the rails without much difficultly.
Nearly a year ago, my boss introduced me to the Unix utility tee. Seeing as at least one of my unix using friends was unaware of the utility, I figured others must not know of it either.
As the documentation puts it; "reads standard input, then writes the output of a program to standard output and simultaneously copies it into the specified file or files." Pretty straightforward.
I believe every unix shop has a locally written script that will run a specified script on a collection of hosts. I've certainly written that script before. Sometimes however I can't write a script that encapsulates my needs. For these needs, I can usually use multixterm.
As the name implies, multixterm runs multiple xterms. The neat part, is that it provides a way to provide the same input to all of those xterms at the same time.
Running the command; multixterm -xc "ssh %n" foo bar baz (where foo, bar, and baz are hostnames), will open three xterm terms. Each window will have already run the command "ssh hostname" (with one hostname per xterm). You will also have a small input window where you can type, and that text appears in all of the spawned xterms. Or, if you have an exception in a particular window, you can go type in that one alone.
Useful tip: take photos of the internal and external wiring of any computers that you install far from workplace/home. I realized how useful this would be on a late night race to Fry's Electronics (a race because Fry's was 3 miles away and was closing in 10 minutes) from my colo provider.
Had I had a picture of the inside of a particular server, I would have
known that there were no free power plugs for hard drives, and that I would
need to bring a y splitter. Instead, I broke a multitude of laws to acquire
one last night. .
