Tip

Optimizing Disk I/O Performance

Optimizing Disk I/O Performance

From Essential Windows NT System Administration by Aeleen Frisch, O'Reilly and Associates, 1998.

Disk I/O can be a major performance bottleneck that can affect a system or individual job. In this tip we will look at some of the factors that can affect disk I/O performance.

  • Filesystem fragmentation degrades I/O performance. Fragmentation results when the free space within a filesystem is scattered in small chunks, rather than fewer large ones of the same total size. This means that files themselves become fragmented (noncontiguous), and access times to reach them become correspondingly longer.

    Filesystem fragmentation tends to increase over time. Eventually, it will be necessary to defragment the filesystem. There are currently several commercially available utilities designed for this purpose.

  • Sequential access of large files (i.e., reading or writing, starting at the beginning and moving steadily toward the end) is most efficient when the files are contiguous: made up of a single, continuous chunk of space on a disk. It may be necessary to defragment or even rebuild a filesystem to create a large amount of contiguous disk space.

  • Disk I/O to large sequentially accessed files is also improved by disk striping.

  • Placing large, randomly accessed files (e.g., databases) in the center portions of disk drives (rather than out on the edges) yields the best performance.

    Requires Free Membership to View

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to:

Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.