Chapter 11.
Using GNBD
This chapter describes how to use a GNBD (Global Network Block Device) and consists of the fol-
lowing sections:
•
Section 11.1
Considerations for Using GNBD Multipath
•
Section 11.2
GNBD Driver and Command Usage
11.1. Considerations for Using GNBD Multipath
GNBD multipath allows you to configure multiple GNBD server nodes (nodes that export GNBDs to
GFS nodes) with redundant paths between the GNBD server nodes and storage devices. The GNBD
server nodes, in turn, present multiple storage paths to GFS nodes via redundant GNBDs. With GNBD
multipath, if a GNBD server node becomes unavailable, another GNBD server node can provide GFS
nodes with access to storage devices.
If you are using GNBD multipath, you need to take the following into consideration:
•
Linux page caching
•
Lock server startup
•
CCS file location
•
Fencing GNBD server nodes
11.1.1. Linux Page Caching
For GNBD multipath, do
not
specify Linux page caching (the
-c
option of the
gnbd_export
com-
mand). All GNBDs that are part of the pool must run with caching
disabled
. Data corruption occurs if
the GNBDs are run with caching enabled. Refer to Section 11.2.1
Exporting a GNBD from a Server
for more information about using the
gnbd_export
command for GNBD multipath.
11.1.2. Lock Server Startup
Lock servers can reside on the following types of nodes: dedicated lock server nodes, GFS nodes,
or GNBD server nodes. In any case, a lock server must be running before the GNBD servers can be
started.
11.1.3. CCS File Location
In a GFS cluster configured for GNBD multipath, the location of CCS files for each node depends on
how a node is deployed. If a node is deployed as a dedicated GFS node, its CCS files can reside on a
GNBD, local storage, or FC-attached storage (if available). If a node is deployed as a dedicated GNBD
server, its CCS files must reside on local storage or FC-attached storage. If a node is deployed as a
dedicated lock server, its CCS files must reside on local storage or FC-attached storage. Because lock
servers need to start before GNBD servers can start, a lock server
cannot
access CCS files through a
GNBD. If a lock server is running on a GFS node, the CCS files for that node must be located on local
storage or FC-attached storage.
Содержание GFS 5.2.1 -
Страница 1: ...Red Hat GFS 5 2 1 Administrator s Guide...
Страница 8: ......
Страница 14: ...vi Introduction...
Страница 24: ...10 Chapter 1 GFS Overview...
Страница 36: ...22 Chapter 4 Initial Configuration...
Страница 84: ...70 Chapter 6 Creating the Cluster Configuration System Files...
Страница 96: ...82 Chapter 8 Using Clustering and Locking Systems...
Страница 126: ...112 Chapter 10 Using the Fencing System...
Страница 132: ...118 Chapter 11 Using GNBD...
Страница 144: ...130 Appendix A Upgrading GFS...
Страница 184: ...170 Appendix B Basic GFS Examples...
Страница 190: ......
Страница 192: ...178...