Customer Focused Testing: Five steps to improved Oracle array-based replication with Continuous Access EVA (5697-7433, March 2008)

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Customer Focused Testing: Five steps

to improved Oracle array-based

replication with Continuous Access EVA

Disk-array-based remote copy infrastructures have been available and in use for over a decade.

When properl

yconﬁgured and deployed, they are capable of providing a timely recovery from

avarietyoff

ailures, including the loss of an entire data center site. This document provides

an overview o

f ﬁve recommended steps that should be used when planning to deploy remote

replicatio

n solutions for Oracle 11g Enterprise Database using Continuous Access EVA as the

remote copy

infrastructure. This document is meant as a companion to the HP whitepaper,

Replication Best Practices for Oracle 11g with ASM & EVA8x00, which can be downloaded

at h

ttp://h71028.www7.hp.com/ERC/downloads/4AA1-5658ENW.pdf.Byleveragingthese

recommendations and best practices, customers can select the optimal replication technology for

their environment, optimize performance, and accelerate implementation, thereby reducing costs and

personnel resources.

1Understandyourenvironment

Before implementing any replication solution, it is important to understand your recovery goals and

the limitations of the available infrastructure. For Oracle Replication, the key information includes:

• Recovery point objective (RPO) – RPO refers to the amount of data loss a customer can tolerate,

speciﬁcally, the point in time to which the customer must be able to recover the data. Some

customers require an RPO of zero. That means that in the event of a site failure, the customer

cannot lose a single committed transaction; they must be able to recover the data back to the

exact time of the disaster. An RPO of greater than zero (for example, 30 minutes) can be handled

differently. An RPO of 30 minutes means the customer can tolerate losing the last 30 minutes

of transactions in the event of a site failure.

• Recovery time objective (RTO) – RTO refers to the maximum amount of time it takes a customer to

get the backup site running after a complete failure at the primary site. This includes the time

to fail over the replicated LUNs to the backup EVA, recover and bring the backup database

online, and redirect any applications to the backup database server. A faster RTO can usually be

accomplished by pre-staging the backup site to the greatest extent possible.

• Data Replication (DR) Group – A DR group is a logical group of virtual disks in a remote

replication relationship with a corresponding group on another array. The virtual disks in a DR

group fail over together, share a write history log (WHL), and preserve write-ordering within the

group. The write-ordering preservation is especially important in database applications in the

event of a failover and recovery. Moreover, it is a requirement for an Oracle database using

ASM, so that the remote copy can be brought online properly.

5697-7433

The information contained herein is subject to change without notice. The only warranties

for HP products and services are set forth in the express warranty statements accompanying

such products and services. Nothing herein should be construed as constituting an additional

warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.

Inc. Microsoft and Windows are U.S. registered trademarks of Microsoft Corporation. Oracle is

a registered trademark of Oracle Corporation and/or its afﬁliates.

The information in this document is subject to change without notice.

5697-7433

1st edition: March 2008

Summary of content (4 pages)

PAGE 1
banner Customer Focused Testing: Five steps to improved Oracle array-based replication with Continuous Access EVA Disk-array-based remote copy infrastructures have been available and in use for over a decade. When properly configured and deployed, they are capable of providing a timely recovery from a variety of failures, including the loss of an entire data center site.
PAGE 2
• Bandwidth – one of the key aspects to replication is a good understanding of bandwidth on the intersite link. If your arrays are within the same data center, building, site location, or city replication is possible over the SAN Fibre Channel link, which typically supports 1, 2, or 4 Gb/sec. For greater distances, FCIP may be necessary. It is also important to understand the link between your two sites. Do you have full access on that link? Perhaps your department is limited to 20% utilization.
PAGE 3
Configure the EVA The database files should be separated using two disk groups on the EVA. • A general best practice for databases is to have two EVA disk groups and two ASM disk groups, with the online files in the main group and the backup files in the second group. This is an HP and Oracle guideline, as documented in the HP white paper HP Best practices for Oracle 10g with Automatic Storage Management (ASM) and HP StorageWorks 8000 Enterprise Virtual Array 8000 at http://h71028.www7.hp.
PAGE 4
• Ensure that the intersite link is adequate for the workload being replicated. Server administrator best practices • Use multiple HBAs for path availability and optimal performance. Previous recommendations for a 2-Gb infrastructure (a minimum of four ports for most workloads and, as highly recommended by HP, eight ports for decision support system (DSS)/data warehouses) can be reduced in a 4-Gb infrastructure.