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Chapter 2 Overview of CCI Operations
2.8.7.1
Command Competition
The CCI commands are asynchronous commands issued via the SCSI interface. Accordingly, if
several processes issue these commands to a single LDEV, the storage system cannot take
the proper action. To avoid such a problem, two or more WR commands should not be issued
to a single LDEV. The command initiators should not issue two or more WR commands to a
single LDEV unless the storage system can receive commands with independent initiator
number * LDEV number simultaneously.
Hitachi RAID
(Command device)
RD/WR command
Command
process
HORCM
(CCI)
Command
process
Command
process
Figure 2.34 HORCM and Command Issue Process
2.8.7.2
Flow of Commands
Figure 2.35 shows the flow of RD/WR command control in a specified LBA#.
Write()
Command area
Input parameter
Edited data
Input data
Read()
Write/read
processing code
Scanning edit data by reading
LDEV
(Target#, LUN#)
Host side
Hitachi RAID side
Figure 2.35 Flow of Command Issue
Содержание TAGMASTORE MK-90RD011-25
Страница 2: ......
Страница 8: ...viii Preface ...
Страница 18: ...xviii Contents ...
Страница 180: ...162 Chapter 3 Preparing for CCI Operations ...
Страница 250: ...232 Chapter 4 Performing CCI Operations Vol Type logical unit LU type e g OPEN V OPEN 9 ...
Страница 370: ...352 Chapter 5 Troubleshooting ...
Страница 388: ...370 Acronyms and Abbreviations ...