Red Hat GFS 5.2.1 -, Administrator'S Manual

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Chapter 5.
Using the Pool Volume Manager
This chapter describes the GFS volume manager — named Pool — and its commands. The chapter
consists of the following sections:
•
Section 5.1 Overview of GFS Pool Volume Manager
•
Section 5.2 Synopsis of Pool Management Commands
•
Section 5.4 Creating a Configuration File for a New Volume
•
Section 5.3 Scanning Block Devices
•
Section 5.5 Creating a Pool Volume
•
Section 5.6 Activating/Deactivating a Pool Volume
•
Section 5.7 Displaying Pool Configuration Information
•
Section 5.8 Growing a Pool Volume
•
Section 5.9 Erasing a Pool Volume
•
Section 5.10 Renaming a Pool Volume
•
Section 5.11 Changing a Pool Volume Minor Number
•
Section 5.12 Displaying Pool Volume Information
•
Section 5.13 Using Pool Volume Statistics
•
Section 5.14 Adjusting Pool Volume Multipathing
5.1. Overview of GFS Pool Volume Manager
Pool is a GFS software subsystem that presents physical storage devices (such as disks or RAID ar-
rays) as logical volumes to GFS cluster nodes. Pool can aggregate storage devices either by concate-
nating the underlying storage or by striping the storage using RAID 0. Pool is a cluster-wide volume
manager, presenting logical volumes to each GFS node as if the storage were attached directly to each
node. Because Pool is a cluster-wide volume manager, changes made to a volume by one GFS node
are visible to all other GFS nodes in a cluster.
Pool is a dynamically loadable kernel module,
pool.o
. When
pool.o
is loaded, it gets registered
as a Linux kernel block-device driver. Before pool devices can be used, this driver module must be
loaded into the kernel. (Once the driver module is loaded, the
pool_assemble
command can be run
to activate pools.)
Pool includes a set of user commands that can be executed to configure and manage specific pool
devices. Those commands are summarized in the next section.
More advanced, special-purpose features of the Pool volume manager are described later in this chap-
ter.