Managing Software RAIDs with EVMS
6
no
vd
ocx
(e
n)
6 Ap
ril 20
07
59
6
Managing Software RAIDs with
EVMS
This section describes how to create and manage software RAIDs with the Enterprise Volume
Management System (EVMS). EVMS supports only RAIDs 0, 1, 4, and 5 at this time. For RAID 6
and 10 solutions, see
Chapter 7, “Managing Software RAIDs 6 and 10 with mdadm,” on page 81
.
Section 6.1, “Understanding Software RAIDs on Linux,” on page 59
Section 6.2, “Creating and Configuring a Software RAID,” on page 65
Section 6.3, “Expanding a RAID,” on page 69
Section 6.4, “Adding or Removing a Spare Disk,” on page 70
Section 6.5, “Managing Disk Failure and RAID Recovery,” on page 71
Section 6.6, “Monitoring Status for a RAID,” on page 74
Section 6.7, “Deleting a Software RAID and Its Data,” on page 79
6.1 Understanding Software RAIDs on Linux
Section 6.1.1, “What Is a Software RAID?,” on page 59
Section 6.1.2, “Overview of RAID Levels,” on page 60
Section 6.1.3, “Comparison of RAID Performance,” on page 61
Section 6.1.4, “Comparison of Disk Fault Tolerance,” on page 61
Section 6.1.5, “Configuration Options for RAIDs,” on page 62
Section 6.1.6, “Guidelines for Component Devices,” on page 62
Section 6.1.7, “RAID 5 Algorithms for Distributing Stripes and Parity,” on page 63
Section 6.1.8, “Multi-Disk Plug-In for EVMS,” on page 65
Section 6.1.9, “Device Mapper Plug-In for EVMS,” on page 65
6.1.1 What Is a Software RAID?
A RAID combines multiple devices into a multi-disk array to provide resiliency in the storage
device and to improve storage capacity and I/O performance. If a disk fails, some RAID levels keep
data available in a degraded mode until the failed disk can be replaced and its content reconstructed.
A software RAID provides the same high availability that you find in a hardware RAID. The key
operational differences are described in the following table:
Table 6-1
Comparison of Software RAIDs and Hardware RAIDs
Feature
Linux Software RAID
Hardware RAID
RAID function
Multi-disk (
md
) driver or
mdadm
RAID controller on the disk array
Summary of Contents for LINUX ENTERPRISE SERVER 10 - STORAGE ADMINISTRATION GUIDE 7-2007
Page 4: ...novdocx en 6 April 2007...
Page 30: ...30 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
Page 42: ...42 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
Page 58: ...58 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
Page 90: ...90 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
Page 100: ...100 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
Page 106: ...106 SLES 10 Storage Administration Guide novdocx en 6 April 2007...
