Red Hat GFS 6.1 -, Administrator'S Manual

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Chapter 1. GFS Overview 3
New and Changed Features with Red Hat GFS 6.1 for Red Hat Enterprise Linux 4
Update 2
Red Hat GFS 6.1 for Red Hat Enterprise Linux 4 Update 2 supports iSCSI and multipath
iSCSI. That is, device mapper multipath (
dm-multipath
) can use iSCSI.
1.2. Performance, Scalability, and Economy
You can deploy GFS in a variety of configurations to suit your needs for performance,
scalability, and economy. For superior performance and scalability, you can deploy GFS in
a cluster that is connected directly to a SAN. For more economical needs, you can deploy
GFS in a cluster that is connected to a LAN with servers that use GNBD (Global Network
Block Device). (For more information about GNBD, refer to Chapter 6 Using GNBD with
Red Hat GFS .)
The following sections provide examples of how GFS can be deployed to suit your needs
for performance, scalability, and economy:
•
Section 1.2.1 Superior Performance and Scalability
•
Section 1.2.2 Performance, Scalability, Moderate Price
•
Section 1.2.3 Economy and Performance
Note
The deployment examples in this chapter reflect basic configurations; your needs might
require a combination of configurations shown in the examples.
1.2.1. Superior Performance and Scalability
You can obtain the highest shared-file performance when applications access storage di-
rectly. The GFS SAN configuration in Figure 1-1 provides superior file performance for
shared files and file systems. Linux applications run directly on GFS nodes. Without file
protocols or storage servers to slow data access, performance is similar to individual Linux
servers with directly connected storage; yet, each GFS application node has equal access
to all data files. GFS supports over 300 GFS nodes.