×

System for estimating access time by deriving from first and second rotational time from rotational time table based on logical address and head movement time

  • US 5,854,941 A
  • Filed: 05/31/1996
  • Issued: 12/29/1998
  • Est. Priority Date: 05/31/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for estimating access time of a rotating storage disk between a source logical block address and a destination logical block address, the disk comprising a plurality of tracks, each track comprising a plurality of sectors, a given sector addressed by a host computer using a logical block address, wherein the plurality of sectors for a given track have consecutively numbered logical block addresses starting from a first logical block address for the given track, the method comprising the steps of:

  • looking up a first rotational time estimate for the source logical block address and a second rotational time estimate for the destination logical block address from a table of rotational time estimates accessed by logical block address number, each entry in the table of rotational time estimates having a value not more than one rotational time of the disk;

    estimating radial distance between a first track having the source logical block address and a second track having the destination logical block address based upon the source logical block address and the destination logical block address;

    looking up a head movement time estimate corresponding to the calculated radial distance in a head movement time estimate table; and

    deriving the estimated access time from the first rotational time estimate, second rotational time estimate and head movement time estimate.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×