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Improving the performance to execute sequential Write & Verify commands

IP.com Disclosure Number: IPCOM000014228D
Original Publication Date: 2001-Jul-23
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 28K

Publishing Venue

IBM

Abstract

Improving the performance to execute sequential Write Verify commands Disclosed is a method to improve the performance score of executing sequential Write Verify command of SCSI HDD (Hard Disk Drive). The Write Verify command is executed one by one also when it is issued sequentially. A Write Verify comamnds are executed in two steps: writing data and verifying them.

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Improving the performance to execute sequential Write & Verify commands

      Disclosed is a method to improve the performance score
of executing sequential

      Write & Verify command of SCSI HDD (Hard Disk Drive).
The Write & Verify
command is executed one by one also when it is issued
sequentially. A Write &

      Verify comamnds are executed in two steps: writing data
and verifying them.

      It spends at least two revolution of media to execute a
Write & Verify command.

      With traditional implementation of Write & Verify
command, the execution time of
sequential Write & Verify commands is simply that of a
Write & Verify command
times number of commands.

      When sequential Write & Verify commands are issued and
queued, the firmware
of HDD can detect that they are sequential, and can
concatenate them to
execute at one time. First, the firmware requests all
data. Second, it completes
the write operation of the concatenated Write & Verify
commands. And at last,
it executes verify operation of the commands and sends
statuses of the
commands. By concatenating sequential Write & Verify
commands, we can
reduce the execution time of sequential Write & Verify
commands dramatically.

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