Data Availability Features; Raid Implementation - IBM TotalStorage DS6000 Introduction And Planning Manual

Data availability features

This section provides information about data availability features that are supported
by DS6000 series.
The DS6000 series provides the following features:
v RAID implementation
v Copy services
v Availability support for open systems, iSeries, zSeries, and pSeries hosts
v Component redundancy to eliminate single points of hardware failure, and no

RAID implementation

RAID implementation improves data storage reliability and performance.
With RAID implementation, the DS6000 series offers fault-tolerant data storage by
storing the same data in different places on multiple disk drive modules (DDMs). By
placing data on multiple disks, input/output operations can overlap in a balanced
way to improve the basic reliability and performance of the attached storage
devices.
Physical capacity for the DS6000 series can be configured as RAID 5, RAID 10, or
a combination of both. RAID 5 can offer excellent performance for most
applications, while RAID 10 can offer better performance for selected applications,
in particular, high random write content applications in the open systems
environment. Each array in the DS6000 series is composed of four drives.
RAID 5 overview
RAID 5 is a method of spreading volume data across multiple disk drives. The
DS6000 series supports RAID 5 arrays.
RAID 5 provides faster performance by striping data across a defined set of DDMs.
Data protection is provided by parity, which redundantly saves the data to the same
DDMs.
RAID 10 overview
RAID 10 provides high availability by combining features of RAID 0 and RAID 1.
The DS6000 series supports RAID 10 arrays.
RAID 0 optimizes performance by striping volume data across multiple disk drives
at a time. RAID 1 provides disk mirroring which duplicates data between two disk
drives. By combining the features of RAID 0 and RAID 1, RAID 10 provides a
second optimization for fault tolerance. Data is striped across half of the disk drives
in the RAID 1 array, and the other half of the array mirrors the first set of disk
drives. Access to data is preserved if one disk in each mirrored pair remains
available.
the opportunity to quickly familiarize yourself with the major aspects of the
DS6000 series and to easily recognize the topics for which you might
require more information. It provides information regarding user assistance
for tasks, concepts, reference, user scenarios, tutorials, and other types of
user information. Using the wonderful search tool and because the
information is all in one place rather than across multiple publications, you
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single point of repair other than the enclosure.
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Chapter 1. Introduction