Migrating an Oracle Database to Dell EMC SC Series Storage Dell EMC Engineering November 2019 A Dell EMC Technical White Paper
Revisions Date Description October 2013 Initial release April 2017 Content review and updates November 2019 vVols branding update Acknowledgements Authors: Mark Tomczik, Henry Wong The information in this publication is provided “as is.” Dell Inc. makes no representations or warranties of any kind with respect to the information in this publication, and specifically disclaims implied warranties of merchantability or fitness for a particular purpose.
Table of contents Revisions.............................................................................................................................................................................2 Acknowledgements .............................................................................................................................................................2 Executive summary....................................................................................................................
3.7.8 Oracle Data Guard............................................................................................................................................22 3.7.9 Oracle GoldenGate ...........................................................................................................................................22 3.7.10 Oracle Streams Replication .........................................................................................................................23 3.7.
Executive summary There are many reasons why database migration happens. Regardless of the reasons, the new platform should introduce newer and better technologies that would ultimately benefit the organization. Dell EMC SC Series storage includes many of these technologies as core features. This document discusses these features, addresses key considerations of migrating Oracle® databases to the SC Series, and introduces some of the most common migration methods and tools available.
1 Introduction 1.1 Audience Migrating Oracle databases to a new platform can be a complex project, especially when the source and target platforms are dissimilar. Typically, a database migration process involves moving or copying data from one platform to another platform by using applications and OS utilities. The OS and storage platforms might both be changed in the process. In addition, the database itself might also be upgraded as part of the migration process.
2 SC Series overview At the center of SC Series is the Storage Center Operating System (SCOS). SCOS incorporates the best of flash technology, powers the storage virtualization, and delivers greater flexibility and economics for both allflash and hybrid arrays. The following list highlights some of the most innovative and core SCOS features.
since the last snapshot. This uses less network bandwidth and less time. In the event of primary array/site failure, the replicas can be activated by the administrator on the remote site. Live Volume is a hyper-volume that stretches across two different SC Series arrays. The feature extends data protection beyond the basic array replication and offers enhanced disaster recovery capability to a remote site.
3 Storage migration planning and considerations 3.1 Understand the environment A database migration involves moving a database from one system to a different system. Migration planning is one of the most critical parts of the migration process.
3.2.1.2 Transactions These are measurements in terms of database transactions and latency. In most cases, the application vendors would have some built-in facilities that allow capturing such information. For an Oracle database, the mostly used utilities are statspack and AWR. AWR is preferred to the older statspack but either one can provide abundant performance statistics of a database. 3.2.
consistency group. SCOS 7.2 has lifted the maximum number of volumes in a single consistency group from 40 to 100. Section 3.3.2 describes the use of a consistency group with taking database snapshots. Volume size: In general, there are no noticeable performance differences in volume sizes. Consider using fewer larger-sized volumes to reduce administration overhead. In Oracle 11gR2, ASM supports volume sizes up to 2 TB. In Oracle 12c, it is drastically increased to 32 PB.
3.3.2 Protecting Oracle with snapshots and a consistency group The SC Series storage snapshot feature can be incorporated into the existing backup/restore strategy. Enabled through the snapshot profile, it protects an Oracle database by creating fast and space-efficient snapshots of the storage volumes. To access or restore data from a snapshot, a view volume is created and mounted with full access on any recovery system.
Storage profiles available with both write SSDs and read SSDs Name Initial write tier Tier (T) and RAID levels Progression Flash Optimized with Progression (Tier 1 to All Tiers) 1 Writes: T1 RAID 10 Snapshots: RAID 5/RAID 6 To all tiers Write Intensive (Tier 1) 1 Writes: T1 RAID 10 Snapshots: T1 RAID 10 Stay in tier 1 Flash Only with Progression (Tier 1 to Tier 2) 1 Writes: T1 RAID 10 Snapshots: T2 RAID 5 To tier 2 Low Priority with Progression (Tier 3 to Tier 2) 3 Writes: T3 RAID 10 Snaps
Volume attributes in DSM 3.4 14 Ingest data By default, data ingestion goes to tier 1 in an SC Series array, but it might not be desirable to consume all tier 1 storage for the migration. A common practice is to direct data during ingestion to the lowest tier where capacity is abundant. In DSM, set the storage profile to Low Priority on each volume for the duration of the ingestion. After the migration is complete, change the storage profile to Recommended or Flash Optimized with Progression.
3.5 Configure Oracle disk groups 3.5.1 Automatic Storage Management (ASM) This section describes some common practices when creating disk groups on an SC Series array. Oracle ASM is the preferred storage management system since Oracle version 11. It provides three levels of storage redundancy which allows data to be mirrored through its software.
Little-endian Big-endian Memory address Physical memory Memory address Physical memory 00 D7 00 10 01 10 01 D7 02 02 03 03 Little-endian and big-endian Because endianness changes how numeric values are represented in memory, failures or corruption can occur during a migration if endianness is ignored. For further information on endian formats and descriptions, refer to the Wikipedia Endianness page. 3.6.
3.6.2 Determine the database endian format To determine the endianness of the source 11gR2 or 12c database, the following query can be executed against dynamic views V$TRANSPORTABLE_PLATFORM and V$DATABASE in both databases. Query the endian format of a database SQL> col platform_name format a36 select tp.platform_name, tp.endian_format from v$transportable_platform tp, v$database d where tp.platform_name = d.
If the endianness of the source and target platforms have different endian formats, an additional step must be executed to correct data conversion of numeric values during a database. The additional step can be performed on either the source or target platform. Omitting this critical step will result in failures or corruption and unsuccessful migration. Refer to the Oracle knowledge base article, How to Migrate to different Endian Platform Using Transportable Tablespaces With RMAN (Doc ID 371556.
3.7.1 Oracle ASM When the database uses Oracle ASM, the storage can be swapped out in the following sequence using ASM online addition/removal and rebalance features: 1. New SC Series volumes are added to the existing disk groups and original volumes are dropped from the disk groups at the same time with a single command. 2. Data is rebalanced automatically by ASM. 3. No application/database outage occurs during the operations. 4. Progress can be monitored by querying the V$ASM_OPERATION.
3.7.3 Linux utilities When the database uses the file system, Oracle data files might be copied to new storage on another system using native OS commands. Popular commands include: tar, cpio, cp, scp, and rsync. Rsync is a very versatile file copying tool. It can be used to copy files locally or to or from a remote system. It can transfer data over the ssh protocol to protect the data during the transfer.
Refer to the following documents and knowledge base articles for more information. Some references may require an Oracle login. • • • • 3.7.6 Master Note for Transportable Tablespaces -- Common Questions and Issues (Doc ID 1166564.1) Transportable Tablespace Restrictions and Limitations: Details, Reference, and Version Where Application (Doc ID 1454872.
3.7.7 RMAN RMAN is a very versatile database backup restore utility that works on versions of Oracle database from Oracle 8 onward. It can be paired with Transportable Tablespaces feature to achieve minimal downtime database migration as mentioned in section 3.7.5. Other RMAN options might be considered to assist in the migration process.
3.7.10 Oracle Streams Replication Oracle Streams has been deprecated in Oracle 12c, though it is still available in 11g. Oracle positions GoldenGate as its successor. It is designed to share information by capturing and queuing messages in one database, propagating them to another database, and then consuming them in the target database. Data can also be transformed as part of the workflow.
4 24 Conclusion Dell EMC SC Series storage works with many different OS platforms and the simplicity in management helps reduce the complexity of storage management in the migration process. This frees up valuable time for administrators to focus more on the migration work that is performed mostly on the OS and Oracle layers and uses many of the Oracle and Linux native tools.
A Technical support and resources Dell.com/support is focused on meeting customer needs with proven services and support. Storage technical documents and videos provide expertise that helps to ensure customer success on Dell EMC storage platforms. A.1 Additional resources Referenced or recommended Dell EMC publications: • • • • • • • • • Dell Storage Center OS 7.
• • • • • Data Guard Support for Heterogeneous Primary and Physical Standbys in Same Data Guard Configuration (Doc ID 413484.1) Methods for Upgrading to Oracle Database 11g Release 2 Upgrading to Oracle Database 12c (12.1.0.2) Changing between 32-bit and 64-bit Word Sizes (Doc ID 62290.
