Linux Server Hacks, Volume Two

Hack #69. Find Resource Hogs with Standard Commands

You don't need fancy, third-party software or log analyzers to find and deal with a crazed user on a resource binge.

There are times when users will consume more than their fair share of system resources, be it CPU, memory, disk space, file handles, or network bandwidth. In environments where users are logging in on the console (or invoking the login utility by some other means), you can use pam_limits,or the ulimit utility to keep them from going overboard.

In other environments, neither of these is particularly useful. On development servers, for example, you could be hosting 50 developers on a single machine where they all test their code before moving it further along toward a production rollout. Machines of this nature are generally set up to allow for things like cron jobs to run. While it's probably technically possible to limit the resources the cron utility can consume, that might be asking for trouble, especially when you consider that there are many jobs that run out of cron on behalf of the system, such as makewhatis and LogWatch.

In general, the developers don't want to hog resources. Really, they don't. It makes their work take longer, and it causes their coworkers to unleash a ration of grief on them. On top of that, it annoys the system administrators, who they know can make their lives, well, "challenging." That said, resource hogging is generally not a daily or even weekly occurrence, and it hardly justifies ...