Installation guide

Chapter 1. Using GNBD with Red Hat GFS
GNBD (Global Network Block Device) provides block-level storage access over an Ethernet LAN. GNBD
components run as a client in a GFS node and as a server in a GNBD server node. A GNBD server
node exports block-level storage from its local storage (either directly attached storage or SAN storage)
to a GFS node.
Table 1.1, “GNBD Software Subsystem Components” summarizes the GNBD software subsystems
components.
Table 1.1. GNBD Software Subsystem Component s
Soft ware Subsystem Components Description
GNBD gnbd.ko Kernel module that implements the GNBD
device driver on clients.
gnbd_export Command to create, export and manage
GNBDs on a GNBD server.
gnbd_import Command to import and manage GNBDs on
a GNBD client.
gnbd_serv A server daemon that allows a node to
export local storage over the network.
You can configure GNBD servers to work with device-mapper multipath. GNBD with device-mapper
multipath allows you to configure multiple GNBD server nodes to provide redundant paths to the storage
devices. The GNBD servers, in turn, present multiple storage paths to GFS nodes via redundant
GNBDs. When using GNBD with device-mapper multipath, if a GNBD server node becomes unavailable,
another GNBD server node can provide GFS nodes with access to storage devices.
This document how to use GNBD with Red Hat GFS and consists of the following chapters:
Chapter 2, Considerations for Using GNBD with Device-Mapper Multipath, which describes some of
the issues you should take into account when configuring multipathed GNBD server nodes
Chapter 3, GNBD Driver and Command Usage, which describes the restrictions that apply when you
are running GFS on a GNBD server node
Chapter 4, Running GFS on a GNBD Server Node, which describes the user commands that
configure GNBD
Red Hat Enterprise Linux 4 Global Network Block Device
8