Managing RAID on Linux

Configuring Hard Disk Parameters

Hard disks, like most computer components, are shipped with certain configurations that manufacturers have determined are ideal for the largest denomination of users. Unfortunately, these default settings often mean that disks are shipped with configurations that make them compatible with the largest number of consumer desktops, as opposed to making them perform as fast as possible. Luckily, many of these parameters can be tuned to meet specific system needs. With the help of system-tuning utilities, these parameters can be modified to increase overall array and standalone disk performance.

Warning

The performance tips covered in this section are meant to be performed on individual disks, not arrays. However, it is essential that you apply any changes uniformly to each component disk in your arrays. Tuning one or more disks and failing to tune others will result in poor, and probably bizarre, performance.

I strongly recommend that anyone who isn’t already familiar with the basic tactics of performance tuning first carefully read http://linuxperf.nl.linux.org/baseline.html. It outlines quite a number of ideas that are essential to successful systems management and stability. There are also many other articles available from http://linuxperf.nl.linux.org/ that make excellent complementary material to the disk I/O-specific information that I will provide in this section.