Disk drive and method for controlling clearance in the disk drive

A disk drive comprising:

• a disk configured to store data;
• a slider configured to fly in proximity to a recording surface of said disk;
• a magnetic-recording head on said slider configured to access said disk;
• a moving mechanism configured to support and to move said head-slider;
• an adjustment portion configured to adjust clearance between said magnetic-recording head and said disk;
• and
• a controller configured to control said adjustment portion to control said clearance, wherein said controller is configured to perform clearance control in a first mode in an operation selected from the group consisting of reading user data and writing user data according to a change in fly height of said slider after a load operation, said clearance control in said first mode based on a pre-defined clearance change profile performed without measuring a clearance between said magnetic-recording head and said disk, and said controller configured to perform subsequently clearance control in a second mode in an operation selected from the group consisting of reading user data and writing user data.