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Continuous Access Overview. Damian McNamara Consultant. Continuous Access (1). CA copies data online and in real time using synchronous replication to remote locations through a local or extended SAN. Mirror Database. Database. Mirror Database. Database. Continuous Access (2).
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Continuous Access Overview Damian McNamara Consultant
Continuous Access (1) CA copies data online and in real time using synchronous replication to remote locations through a local or extended SAN Mirror Database Database
Mirror Database Database Continuous Access (2) • Host is not aware of remote location • Host writes its data to a LUN
Mirror Database Database Continuous Access (3) • Source controller writes data in its cache • CA EVA copies data to remote controllers cache
Mirror Database Database Continuous Access (4) • Remote controller sends ACK to local controller • Remote host writes data to a data disk
Mirror Database Database Continuous Access (5) • Local controller informs host that I/O is completed
Dest VOL Dest VOL Continuous Access EVA Remote copying • What does it do? • Replicates LUNs between EVAs • Provides disaster recovery • Simplifies workload management • Allows point-in-time database backup • Provides restore without latency • Business drivers • Creates up to 128 Copy Sets for all specified logical units in the array over Fibre Channel and FC extensions • Synchronous and asynchronous support up to 20’000km (200ms round trip time) • Works with all EVAs Copy Set Source VOL Source VOL Copy Set
DR Group Consistent Group of replicated copy sets (Vdisks) Up to 32replicatedcopy sets per DR Group IO ordering across members is guaranteed Share a single write history log Vdisks within a DR Group behave like a single entity Management commands like suspend or failover are handled atomicaly All source members online on same HSV controller Therefore a DR Group is the primary level of CA management Write Mode ([Synchronous] / Asynchronous) Failsafe Mode (Enabled or [Disabled]) Suspend Mode ([Resume] / Suspend) Failover command Managed Sets Another level of CA management Collection of DR groups for the purpose of common management No consistency as between members of a DR Group If you perform a management command on a Managed Set this command will be run for all contained DR Group one after the other DR groups and managed sets Vdisk DR Group Managed Set
Fan-in of multiple relationships The ability of one EVA to act as the destination for different LUNs from more than one source EVA Fan-out of multiple relationships The ability for different LUNs on one EVA to replicate to different destination EVA Bidirectional one array with copy sets acting as the source and destination across the same intersite links or fabric EVA3000 EVA4000 EVA5000 EVA6000 EVA8000 Multiple relationships EVA6000 EVA8000 EVA5000
What does it do? Provides manual or automated site-failover for Server and Storage resources Supported environments: Microsoft Windows 2003 Enterprise Edition (32-bit & 64-bit) Microsoft Windows 2003 Data Center Server(64-bit) NAS4000 & 9000 HP Proliant DL380/580 Storage Server Microsoft Cluster Service 5.2 Up to 500km Requirements: EVA Disk Arrays Cluster Extension EVA Continuous Access EVA Max 20ms network round-trip delay Command View EVA & SMI-S Cluster extension EVA for Windows MSCS on Windows Cluster Extension EVA HP ContinuousAccess EVA DataCenter 1 DataCenter 2 Up to 500km
App A App A App B App B Quorum DRG A DRG B Windows 2003 stretched cluster with CA – Majority Node Set (MNS) Quorum Quorum • CA Failover • Restart Servers(Rescan) Continuous Access EVA
Quorum Cluster extension EVA: – Manual move of App A App A App A App B Quorum Quorum • Move App A DRG A Continuous Access EVA DRG B
App A App A App B App B Quorum DRG A DRG B Cluster extension EVA:- Storage failure Quorum Quorum Continuous Access EVA
Questions ? Delivering Enterprise Computing Solutions