The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 1999
Filed:
Jan. 30, 1997
Gerald E Smith, Boynton Beach, FL (US);
AIWA Co., Ltd., Tokyo, JP;
Abstract
A RAID system that uses non-volatile random access memory (NVRAM) to greatly reduce the chance of loss of data due to an AC power failure. This RAID system has two write modes. In a normal write mode, a host computer receives a write confirmation once an array controller receives data from the host computer. In a safe write mode, however, the array controller copies to NVRAM all data received from the host computer for writing to disk drives. In this safe write mode, the array controller sends the write confirmation to the host computer only after storing the data in NVRAM. To switch appropriately between the normal and safe write modes, the array controller polls a power-out flag provided by a UPS (uninterruptable power supply) to determine whether there has been an AC power failure. The array controller switches between the two write modes depending on the status of the power-out flag.