One well-known way to optimize disk I/O is to keep the system from crossing track boundaries. However, this doesn't always work with Windows 2000 because of some peculiarities of the NTFS file system.
Windows 2000's Master Boot Record limits the number of hidden sectors to 63, which causes the default starting sector of disks that show more than 63 sectors per track to be sector 64. This can cause track misalignment, which defeats efforts not to cross track boundaries.
The problem is further complicated by the characteristics of today's disks and controllers. Some disks don't accurately report track information to avoid other problems. Disks can also have a different number of sectors on the inner and outer tracks. This is an effort to improve performance by keeping the number of sectors per second passing under the heads more or less constant.
You can avoid the track misalignment by using Windows 2000 APIs to obtain and set the partition information for the disks. The Windows 2000 Resource Kit companion CD includes a program called diskpar.exe that shows how to do this.
For more information on tuning disk performance in Windows 2000, see Chapter 8 of the Windows 2000 Server Resource Kit available at www.microsoft.com.
For more information:
Tip: Move the pagefile, and go faster
Tip: What causes slow startup in Windows 2000?
Tip: Nuances of Windows NT and SCSI disk performance
About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
