116
Chapter 11. Using GNBD
Caution
For GNBD multipath, you must not specify the
-c
option. All GNBDs that are part of the pool
must run
with caching
disabled
. Pool, the GFS volume manager, does not check for caching
being disabled; therefore, data corruption will occur if the GNBD devices are run with caching
enabled.
Note
If you have been using GFS 5.2 or earlier and do
not
want to change your GNBD setup you
should
specify the
-c
option. Before GFS Release 5.2.1, Linux caching was enabled by default
for
gnbd_export
. If the
-c
option is
not
specified, GNBD runs with a noticeable performance
decrease. Also, if the
-c
option is
not
specified, the exported GNBD runs in timeout mode,
using the default timeout value (the
-t
option). For more information about the
gnbd_export
command and its options, see the
gnbd_export
man page.
-P
PortNumber
GNBD Port — Required for GNBD multipath.
PortNumber
specifies the port number on
which to export a GNBD. The
-P
option is required for automatic reconnection. In order for a
GNBD client to automatically reconnect to a GNBD server when Pool (the GFS volume man-
ager) tries to reintegrate paths, the GNBD server must be at the same IP address and port as it
was previously. If the
-P
option is
not
specified, a random port number is chosen.
11.2.1.2. Examples
This example is for a GNBD server configured with GNBD multipath. It exports device
/dev/sdc2
as GNBD
gamma
. Cache is disabled by default. A port number 2345 is specified.
gnbd_export -d /dev/sdc2 -e gamma -P 2345
This example is for a GNBD server
not
configured with GNBD multipath. It exports device
/dev/sdb2
as GNBD
delta
with cache enabled.
gnbd_export -d /dev/sdb1 -e delta -c
11.2.2. Importing a GNBD on a Client
The
gnbd.o
kernel module must be loaded on a node before it can import GNBDs. When GNBDs
are imported, device nodes are created for them in
/dev/gnbd/
with the name assigned when they
were exported.
11.2.2.1. Usage
gnbd_import -i
Server
Server
Specifies a GNBD server by hostname or IP address from which to import GNBDs. All GNBDs
exported from the server are imported on the client running this command.
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...