Developers Guide

Technology overview
7 Dell EMC SC Series Storage with Oracle ASM | CML1111
2 Technology overview
2.1 SC Series storage
SC Series storage provides features that can be used in an Oracle database environment to create a robust
storage solution and assist DBAs with data tiering, database performance, efficient use of storage, and
database activities. For information on SC Series storage and Oracle, see the best practices document, Dell
EMC SC Series Arrays and Oracle.
2.2 Oracle technology
ASM is an alternative to other conventional volume managers, file systems, and raw devices. It provides a
simplified storage management interface for DBAs. Broadly speaking, ASM is a logical volume manager that
virtualizes storage to a set of disk groups and provides redundancy options to enable a high level of
protection. Oracle recommends using ASM for storage management.
Flex ASM is an enhanced version of ASM that is offered in Oracle 12c. Flex ASM provides the capability to
change the architecture of the ASM cluster, and provides a way to mitigate database instance outages should
the ASM instance running on the database server sustain an outage.
With respect to the physical storage, there is no difference on how storage should be configured for ASM or
Flex ASM. The configuration can be the same. The difference between ASM and Flex ASM is how ASM is
configured. With no difference in physical configuration between ASM or Flex ASM implementations, the use
of SC Series storage features remains the same between the ASM and Flex ASM implementations.
2.3 Oracle ASM features
Oracle ASM was introduced in Oracle 10g and provides a vertical integration of the file system and a volume
manager specifically built for only Oracle database files. ASM can assemble multiple disk devices that behave
as block devices into logical containers called disk groups, and can perform non-intrusive storage
configuration, striping, and mirroring within the disk groups with automatic rebalancing. ASM distributes I/O
loads across all available disk devices within disk groups to optimize performance and resource utilization,
while removing the need for manual I/O tuning by spreading out the database files to avoid hotspots. ASM
also helps DBAs manage a dynamic database environment by allowing database growth and transparent
data relocation among the disk devices without having to shut down the database to adjust storage allocation.