| 摘要 |
In a storage system using multiple disk drives, the disk drive spindles are rotated at the same frequency and at a predetermined phase relationship. A phase angle, measured as the difference between an index mark recorded on the disk and the disk's read head, is used to control the spindle rotation speed. Each of the disk drives are first independently frequency locked to a target frequency, and once frequency locked, each disk drive is phase locked in relation to one another. In the phase locking process, each disk generates a synchronizing signal for synchronizing the rotation of the disks to a predetermined phase relationship. If any one of the disk drives becomes inoperable (due to a failure or "hot-swapping"), the other disk drives remain synchronized since the synchronizing signal is not lost.
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