Red Hat GNBD WITH GLOBAL FILE SYSTEM 5.2 Configuration And Administration Manual page 16

Chapter 3. GNBD Driver and Command Usage
Note
A server should not import the GNBDs to use them as a client would. If a server
exports the devices uncached, the underlying devices may also be used by
Usage
gnbd_export -dpathname-egnbdname [-c][-u][-U
pathname
Specifies a storage device to export.
gnbdname
Specifies an arbitrary name selected for the GNBD. It is used as the device name on GNBD
clients. This name must be unique among all GNBDs exported in a network.
-o
Export the device as read-only.
-c
Enable caching. Reads from the exported GNBD and takes advantage of the Linux page
cache.
By default, the
gnbd_export
Note
When you configure GNBD servers with device-mapper multipath, do not specify
the option. All GNBDs that are part of a logical volume must run with caching
-c
disabled.
Note
If you have been using GFS 5.2 or earlier and do not want to change your GNBD
setup you should specify the
caching was enabled by default for
specified, GNBD runs with a noticeable performance decrease. Also, if the
option is not specified, the exported GNBD runs in timeout mode, using the
default timeout value (the
gnbd_export
6
command does not enable caching.
option. Before GFS Release 5.2.1, Linux
-c
gnbd_export
option). For more information about the
-t
command and its options, refer to the
. If the option is not
-c
man page.
gnbd_export
.
gfs
-c