Product manual

CDA 7 5630 Product Manual
viii 77 A1 69UP Rev00
2.4.3 SRDF Remote Link Director ...........................................................................2-9
2.4.4 Disk Director ................................................................................................2-10
2.4.5 Cache ..........................................................................................................2-10
2.5 Channel Attachments................................................................................................2-11
2.5.1 Ultra SCSI Channel Attachement .................................................................2-11
2.5.2 Fibre Channel Attachments ..........................................................................2-12
3. CDA 7 Input/Output Operations
3.1 ICDA Operation...........................................................................................................3-1
3.1.1 Cache Management .......................................................................................3-2
3.1.1.1 LRU Algorithm................................................................................3-3
3.1.1.2 Prefetch Algorithm..........................................................................3-4
3.1.2 Caching Techniques.......................................................................................3-4
3.2 Elements of a CDA 7 I/O Operation.............................................................................3-6
3.2.1 I/O Response Time ........................................................................................3-6
3.2.2 Read Operations............................................................................................3-9
3.2.2.1 Read Hit .......................................................................................3-10
3.2.2.2 Read Miss ....................................................................................3-11
3.2.3 Write Operations ..........................................................................................3-11
3.2.3.1 Fast Write.....................................................................................3-13
3.2.3.2 Delayed Fast Write.......................................................................3-14
4. Performance Features
4.1 Cache.........................................................................................................................4-1
4.2 Multiple Channel Directors ..........................................................................................4-1
4.3 Parallel Processing .....................................................................................................4-1
4.4 Fast Write Capabilities ................................................................................................4-2
4.5 Dynamic Mirror Service Policy.....................................................................................4-2
4.6 RPS Miss Elimination..................................................................................................4-2
4.7 Channel Speed ...........................................................................................................4-2
5. Managing Critical Data
5.1 CDA 7 Data Management Overview............................................................................5-1
5.1.1 CDA 7 Reliability and Availability Features .....................................................5-1
5.1.2 CDA 7 Data Integrity Protection Features .......................................................5-2
5.1.3 Data Protection Options .................................................................................5-3
5.1.3.1 RAID-1 Option (Mission Critical/ Business Critical)..........................5-3
5.1.3.2 CDA 7 Remote Data Facility (SRDF) ..............................................5-3