Sequential Access I/O

You can optimize the performance of your configuration to take advantage of a sequential I/O environment, such as DBMS servers that are dominated by full table scans and NFS servers in very data-intensive environments, by setting the interlace value low relative to the size of the typical I/O request.

For example, assume a typical I/O request size of 256 Kbyte and striping across 4 spindles. A good choice for stripe unit size in this example would be: 256 Kbyte / 4 = 64 Kbyte, or smaller.

This strategy ensures that the typical I/O request is spread across multiple disk spindles, thus increasing the sequential bandwidth.

Seek time and rotation time are practically zero in the sequential case. When you optimize sequential I/O, the internal transfer rate of a disk is most important.

In sequential applications, the typical I/O size is usually large (greater than 128 Kbytes, often greater than 1 Mbytes). Assume an application with a typical I/O request size of 256 Kbytes and assume striping across 4 disk spindles. 256 Kbytes / 4 = 64 Kbytes. So, a good choice for the interlace size would be 32 to 64 Kbyte.