Monitoring and Tuning Performance on Linux

On a modern stand-alone system, Linux is pretty quick, and if it isn’t, there’s something wrong — something that is up to the system administrator to fix. You might have a number of people using the same fileserver,
mail server, or other shared machine, in which small improvements in system performance can mean a lot.

System tuning is an ongoing process carried by a variety of  monitoringtools. Some performance decisions are made at installation time, while others are added or configured later.

Proper monitoring can detect a misbehaving application that might be consuming more system resources than it should or failing to exit completely on close. Through the use of system performance tools you can determine when hardware — such as memory, added storage, or even something as elaborate as a hardware RAID — should be upgraded for more cost-effective use of a machine in the enterprise. Possibly most important, careful system monitoring give you an early idea when a system component is showing early signs offailure, so that any potential downtime can be minimized.

Careful system monitoring and built-in configurability of Linux allows you to squeeze the best possible performance from your existing equipment, from customizing video drivers to applying special kernel patches to simply turning off unneeded services to free memory and processor cycles.

All of these points about taking care of your servers and making sure silly things don’t cause them to crash  from a long-time UNIX philosophy: Uptime is good. More uptime is better.

The UNIX (Linux) uptime command tells the user how long the system has been running since its last boot, how many users are currently logged in, and how much load the system is experiencing. The last two are useful measures that are necessary for day-to-day system health and long-term planning. (For example, the server load has been staying high lately, so may be it’s time to buy a faster/bigger/better server.)

But the all-important number is how long the server has been running since its last reboot. Long uptimes are a sign of proper care, maintenance, and, from a practical standpoint, system stability. You’ll often find UNIX administrators boasting about their server’s uptimes the way you hear car buffs boast about horsepower. This is also why you’ll hear UNIX administrators cursing at system changes (regardless of operating system) that require a reboot to take effect, even though applying the latest kernel security patch may justify that reboot. You may deny caring about it now, but in six months you’ll probably scream at anyone who reboots the system unnecessarily. Don’t bother trying to explain this phenomenon to a nonadmin, because they’ll just look at you oddly. You’ll just know in your heart that your uptime is better than theirs.

For more articles and learning Linux system administration visit http://www.linuxadministrationguide.com