Snapshot and FlexClone
Several of the capabilities of NetApp storage contribute to the ease of Oracle data management in NFS environments. NetApp Snapshot copies are space-efficient, point-in-time copies that can be created in a matter of seconds. To create an Oracle backup, you only need to put the database in hot backup mode for a few seconds while a Snapshot copy is being created. The impact to operations is usually negligible, so most DBAs schedule multiple Snapshot copies throughout the day as a safety net. You can retain up to 255 Snapshot copies of each storage volume and restore individual files from previous Snapshot copies or revert to a previous copy if a problem occurs.
Typically, IT shops using Oracle keep a number of Snapshot copies on primary storage to meet immediate needs. Snapshot copies can also be copied to secondary storage using NetApp SnapVault®, mirrored to a remote disaster recovery site using SnapMirror®, backed up to tape, or any combination of these options—whatever is necessary to meet data protection requirements. Because these operations occur on the storage system, there is no impact to running Oracle applications.
NetApp FlexClone® is another option that has proven to be highly useful in Oracle and other database environments. FlexClone allows you to create a writeable clone of any data volume. New disk space is consumed only as the original volume and the clone deviate from each other. This means that you can easily clone production data for test and development, data mining, or other purposes without the typical 2X storage requirement. As with Snapshot, you can create up to 255 FlexClone volumes of a single volume. (A recent Tech OnTap case study described the use of FlexClone to streamline Oracle application development and test.)
NetApp has also created a number of value-added software tools specifically for Oracle environments.
SnapManager for Oracle
SnapManager® for Oracle is a management tool that simplifies the management of Oracle backup and recovery. It works across all storage protocols and integrates closely with Oracle ASM and RMAN. SnapManager for Oracle makes it easy to schedule the creation of consistent Snapshot copies and FlexClone volumes, enabling operations that previously required complicated scripts to be accomplished with a few clicks or scheduled for regular execution.
SnapValidator for Oracle
In rare fault conditions, data can get corrupted on the data path between server and storage. Oracle keeps a checksum on each block so that this corruption is detected, but in many cases it may be months before data is actually reread and checked, resulting in the need to recover from a very old backup. To address this issue, SnapValidator® for Oracle complies with the Oracle hardware assisted resilient data (HARD) initiative to verify the checksum and block offset every time a block is written. When a problem is detected the write is failed, forcing the server to repeat the write so that no restore is required.This feature works particularly well with NFS. Traditional host file systems cannot support HARD validation due primarily to the mixture of database blocks and file system metadata in writes to the storage system. Under Oracle 9i, HARD validation is practical only for raw disk and NFS; Oracle 10g extended that capability to Oracle ASM.
SnapLock Integration with Oracle
Oracle includes partitioning and transportable tablespace capabilities that make it possible to relocate subsets of your data to different storage. SnapLock® integration makes it possible to relocate content and messages from Oracle to write once, read many (WORM) volumes. This ensures that the data cannot be modified, helping to meet the requirements of Sarbanes-Oxley (SOX), HIPAA, and other regulatory guidelines. This feature is particularly advantageous with NFS because of the finer level of granularity that NFS provides; you can choose to use SnapLock on a particular file or sets of files. In a SAN environment, you would have to use SnapLock on an entire LUN.