HP XP7 Storage - Manual (Page 3)

Contents
1 Continuous Access Synchronous Z overview...................................................8
How Continuous Access Synchronous Z works .............................................................................8
Typical components .................................................................................................................9
Storage systems .......................................................................................................................9
Volume pairs .........................................................................................................................10
Data path .............................................................................................................................10
Consistency groups ................................................................................................................10
Interfaces ..............................................................................................................................10
Failover software ...................................................................................................................11
Error reporting communications ...............................................................................................11
Overview of initial, update copy operations ..............................................................................11
Initial copy .......................................................................................................................11
Update copy ....................................................................................................................12
2 Requirements and specifications.................................................................13
System requirements and specifications......................................................................................13
Business Continuity Manager specifications ...............................................................................15
Options not supported by Business Continuity Manager..........................................................15
Command device ..............................................................................................................16
F/M = FB message output control option ..............................................................................16
PPRC specifications, restrictions ................................................................................................17
Continuous Access Synchronous Z operations performed with PPRC .........................................17
Continuous Access Synchronous Z options not supported with PPRC .........................................17
PPRC, BCM command comparison.......................................................................................18
SAID values for CESTPATH/YKBLDPTH.......................................................................................19
P/DAS support, restrictions .....................................................................................................21
Restrictions........................................................................................................................22
GDPS support .......................................................................................................................22
RMF PPRC link path statistical information support.......................................................................22
Planning for Basic HyperSwap function—TPC-R support ..............................................................24
Requirements.....................................................................................................................25
Recommendations..............................................................................................................25
Planning for Extended Address Volume......................................................................................25
RAID Manager support for Continuous Access Synchronous Z operations.......................................26
Supported operations and options ......................................................................................26
3 Planning for Continuous Access Synchronous Z.............................................28
Storage system preparation......................................................................................................28
Cache, additional shared memory requirements.....................................................................28
DASD fast write requirements...............................................................................................29
Requirements for XP7 with earlier model storage systems.........................................................29
S-VOL Read and other system options...................................................................................29
System performance considerations...........................................................................................31
Determining Round Trip Time...............................................................................................31
Determining Minimum Number of Remote Paths.....................................................................32
Analyzing workload, planning data paths.............................................................................32
Planning pairs and pair volumes...............................................................................................34
Pair volume requirements and recommendations....................................................................34
Precautions for duplicate VOLSERs.......................................................................................35
About allowing I/O to the S-VOL.........................................................................................36
Allowing I/O to the P-VOL after a split—Fence Level options....................................................36
Differential data ................................................................................................................37
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