US 5,673,412 A · Disk system and power-on sequence for the same

Abstract

With respect to the disk drives provided power from a single power source in a disk drive system, start up power is first supplied to a first start-up group of the disks, preferably comprising all of the master disks, with the size of the group being selected so that the required current does not exceed the capacity of the power source. When the disk drives of the first group have substantially reached steady state, start-up is conducted with respect to a second start-up group of the disk drives so that the current required during start-up for the second group and the current required for steady state drive of the first start-up group does not exceed the capacity of the power source. With respect to each start-up group, the number of disk drives is the maximum integer value and decreases or remains the same with respect to subsequent start-up groups. When simultaneously transferring subdivided data in parallel to all of the disk drives of a parity group, respectively, seek operations in such a system are prevented from occurring simultaneously by offsetting the indices on the disks, by varying the seek operation start timing or by varying the head addresses for the start of reading and writing, all within one revolution, but the seek operations are ended at the same time, to reduce peak current requirements of the power source.

Claims67

Dependent claims

An array disk system for use with a host device, comprising:

a plurality of disk drives;
each disk drive having at least one element that draws steady state current from a power source during a steady state operation including a power off state and larger transient current during transitional operation including a power on state;
and
means, responsive to a signal commanding simultaneous change of the steady state operation to the transitional operation for a plurality of said elements of a plurality of said disk drives, for offsetting respective initiations of at least two of the transitional operations of a respective plurality of said disk drives so that the at least two of the transitional operations do not overlap in time and so that a sum of the transient currents for the at least two of the transitional operations are less than a sum of the transient currents that would exist without the offsetting.

1 more element

In a method of operating an array disk system for use with a host device and having a plurality of disk drives, wherein each disk drive has at last one element that draws steady state current from a power source during steady state operation including power off and larger transient current during transitional operation including power on from a power source, the improvement comprising:

in response to a signal commanding change of the steady state operation to the transitional operation for a plurality of the elements of a plurality of the disk drives, offsetting initiation of at least two of the transitional operations of different disk drives with respect to each other so that the at least two of the transitional operations do not overlap in time and so that transient current demands on the power source for the at least two of the transitional operations are reduced over the transient current demands that would exist without the offsetting.

An array disk system for use with a host device, comprising:

a plurality of disk drives arranged in start up groups, wherein each disk drive has at least one element that draws steady state current from a power source during steady state operation including power off and larger transient current during transitional operation including power on from a power source;
means, responsive to a signal commanding change of the steady state operation to the transitional operation for a plurality of the elements of a plurality of the disk drives, for offsetting initiation of at least two of the transitional operations of different disk drives with respect to each other so that the at least two of the transitional operations do not overlap in time and so that transient current demands on the power source for the at least two of the transitional operations are reduced over the transient current demands that would exist without the offsetting;
means for reading and writing subdivided data in parallel with respect to the plurality of disk drives;
means for driving the plurality of disk drives with a power source providing a steady state current during steady state operation driving of the disk drives;
means for power-on starting up a first start-up group having a plurality of the disk drives with current from the power source for a first period of time of transitional operation until the first start-up group attains the steady state operation;
means responsive to the end of the first period of time, for starting up a second start-up group having a plurality of the disk drives with current from the power source for a second period of time of transitional operation until the second start-up group attains the steady state operation while continuing to rotate the first start-up group at the steady state operation;
and
means for thereafter starting any remaining start-up groups until all of the disk drives have attained steady state driving.

5 more elements

Dependencies are inferred from the claim text.

Disk system and power-on sequence for the same

Life of this patent

Disk system and power-on sequence for the same

Life of this patent

Abstract

Claims67