Patent ID: 6622206
Filing Date: 2003-09-16
Classification: G06F

Abstract:
A method for controlling write cache transfer to sequentially transfer a unit of data from outside of a storage device to a write cache buffer provided in said storage device that writes write cached data on a recording medium, said method comprising:setting an initial value, Ti , equal to F/N, where F is a data capacity of the buffer, N>1, said value Ti is an initial value of a value T, and said value T is a full capacity of a virtual buffer; determining if an amount of write cached data S reaches said virtual buffer full capacity T, said amount S being increased by said write cache transfer and decreased by writing from said write cache to said recording medium; setting a transfer rate of a unit of data lower while an amount of said write cached data S is not less than said initial value Ti of said virtual buffer full capacity than a transfer rate while an amount of said write cached data S is less than said initial value Ti of said virtual buffer full capacity; enabling data transfer during a period where said amount of said write cache data S is less than said value T; in response to said value S being equal to said value T such that said virtual buffer is at said full capacity, inhibiting said data transfer until said value S is less than said value T such that said virtual buffer is no longer full; and resetting said virtual buffer full capacity T to a larger value each time writing of said data transferred from said cache to said storage device is stopped while said virtual buffer remains full.