Novell LINUX ENTERPRISE SERVER 10 - STORAGE ADMINISTRATION GUIDE FOR EVMS, Administration Manual

Page: 11 / 93

Overview of EVMS
1
no
vd
ocx (
E
NU)
9
Jan
uar
y 2
007
11
1
Overview of EVMS
The Enterprise Volume Management System (EVMS) 2.5.5 management tool for Linux* is an
extensible storage management tool that integrates all aspects of volume management, such as disk
partitioning, the Logical Volume Manager (LVM), the Multiple-Disk (MD) manager for software
RAIDs, the Device Mapper (DM) for multipath I/O configuration, and file system operations.
Š Section 1.1, “Benefits of EVMS,” on page 11
Š
Section 1.2, “Plug-In Layers,” on page 11
Š Section 1.3, “File Systems Support,” on page 12
Š
Section 1.4, “Terminology,” on page 12
Š Section 1.5, “Location of Device Nodes for EVMS Storage Objects,” on page 13
1.1 Benefits of EVMS
EVMS provides the following benefits:
Š
Is an open source volume manager
Š Provides a plug-in framework for flexible extensibility and customization
Š
Allows plug-ins to extend functionality for new or evolving storage managers
Š Supports foreign partition formats
Š
Is cluster-aware
1.2 Plug-In Layers
EVMS abstracts the storage objects in functional layers to make storage management more user-
friendly. The following table describes the current EVMS plug-in layers for managing storage
devices and file systems:
Table 1-1
EVMS Plug-In Layers
Storage Managers Description Plug-Ins
Device Manages the physical and logical
devices Device Mapper (DM)
Segment Manages the partitioning of
physical and logical devices into
smaller segments of free space.
Segment managers can be
stacked. For example, a cluster
segment can contain other
storage objects or volumes.
Uses Device Mapper (DM)
Segment managers include DOS,
GPT, System/390* (S/390),
Cluster, BSD, Mac, and BBR
For more information, see
Section 4.1, “Understanding Disk
Segmentation,” on page 33
.