HP XP P9500 Storage - Manual (Page 3)

Contents
1 Continuous Access Synchronous overview......................................................6
How Continuous Access Synchronous works ................................................................................6
Typical components .................................................................................................................7
Storage systems .......................................................................................................................7
Primary (MCU), secondary (RCU) systems...............................................................................8
Volume pairs ...........................................................................................................................8
Data path ...............................................................................................................................9
Consistency groups ..................................................................................................................9
Interfaces ..............................................................................................................................14
Failover software ...................................................................................................................14
Overview of initial, update copy operations ..............................................................................14
Initial copy .......................................................................................................................15
Update copy ....................................................................................................................15
2 Requirements and specifications.................................................................16
System requirements ...............................................................................................................16
3 Planning for Continuous Access Synchronous...............................................18
Preparing P9500 systems.........................................................................................................18
Ensuring adequate cache....................................................................................................18
Installing or removing cache memory or shared memory.........................................................18
Using an earlier model storage system..................................................................................18
Planning for system performance..............................................................................................19
Planning volume pairs.............................................................................................................20
Volume pair requirements and recommendations....................................................................20
Planning I/O to the S-VOL..................................................................................................21
Managing differential data.................................................................................................21
Maximum number of pairs supported...................................................................................22
Calculating maximum number of pairs.............................................................................22
Priority set for initial copy operations and scheduling order.....................................................23
Planning data paths................................................................................................................25
Amount of bandwidth required............................................................................................25
Fibre Channel requirements.................................................................................................25
Supported data path configurations.....................................................................................26
Planning ports...................................................................................................................27
Port requirements...........................................................................................................28
Planning consistency groups.....................................................................................................28
Consistency group requirements...........................................................................................28
Ensuring consistent status for pair suspensions, path failure......................................................28
Other split/suspend behavior with consistency groups.......................................................30
Host failover software..............................................................................................................30
4 Sharing Continuous Access Synchronous volumes.........................................31
Volume types that can be shared with Continuous Access Synchronous..........................................31
Continuous Access Journal.......................................................................................................32
Business Copy........................................................................................................................33
Configurations with Business Copy P-VOLs.............................................................................33
Configurations with Business Copy S-VOLs............................................................................34
Status reporting, data currency............................................................................................34
LUN Expansion......................................................................................................................35
Virtual LVI/LUN......................................................................................................................35
Cache Residency....................................................................................................................35
LUN Manager........................................................................................................................36
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