InfoWorld on Switching to Linux

brentlaminack writes "The latest Infoworld is running a lengthy piece about The Real Cost of Switching to Linux, where it makes sense and where it doesn't. As one of their columnists points out, the debate has switched from "if" to "where". One of the big wins for Linux was in the area of remote administration. Specifically noted was ssh. Also of note is the shift in calculating cost from TCO (Total Cost of Ownership) as has been calculated in the past, to ROI (Return on Investment) that focuses more on what you can do with the technology to get work done."

Comments

Remote management w/ SSH.

[Black Parrot]

> One of the big wins for Linux was in the area of remote administration. Specifically noted was ssh.

I admin ~25 machines remotely, most of them in a room that I don't even have access to without special arrangements. With SSH I can do that without ever having to make those arrangements, except in the case of a major upgrade or a hardware failure.

You can write scripts that will take a shell command as an argument and then step through all your machines executing it on each in turn, greatly simplifying remote management.

You can also use pipes and redirects to channel information between processes on the remote machine and your local machine, e.g. -

ssh remotehost cat /proc/cpuinfo | grep flags > temp.txt

will put the flags in temp.text on your local machine, but -

ssh remotehost "cat /proc/cpuinfo | grep flags > temp.txt"

will put it on the remote machine instead.

Or, if you want to do all the work on the remote machine and only redirect the output to your local machine, use -

ssh remotehost "cat /proc/cpuinfo | grep flags" > temp.txt

and the grep will actually execute on remotehost.

The example is trivial, but you can do some powerful sysadmin stuff that way. However, there are a few gottchas: a few services crap out if you try to restart them with -

ssh remotehost service xyz restart

so you do have to be careful about some things. (Sure wish someone would figure out what causes that and fix it!)