The "anticipatory" elevator - "If you build it - they will come"

• Anticipates that after some I/O - its friends will come.
• In that respect - it is similar to the deadline scheduler.
• However, it also avoids sending other I/O requests (from different "streams") for a certain amount of time.
• In that sense, it does not push too many I/O requests simultaneously to the disk, except when there is a long stream of I/Os.
• Which means it could be better for throughput, but worse for latency.

Originally written by guy keren