Provided by: gnbd-server_1.20060222-0ubuntu5_i386
gnbd_export - the interface to export GNBDs
gnbd_export exports local block devices or files as GNBDs.
This option forces all server processes to send a ping message
to the clients they are connected to. This forces servers with
faulty connections to quit.
-c Enable caching.
Reads from the exported GNBD will take advantage of the linux
page cache. This option is used with -e. NOTE: If this option
is not specified, gnbd will run with a noticeable performance
decrease. Also, if this option is not specified, the exported
GNBD will run in timeout mode, with the default timeout (see the
-t option). With the -c option, it is not necessary to have the
gnbd server machine be part of the cluster. If -c option is not
used, the server machine must already have a cluster manager
running on it. When the first uncached gnbd is exported, the
gnbd_clusterd daemon will be started. This daemon connects to
the cluster manager via the magma interface. WARNING: You must
NOT specify this option if you wish to use gnbd with dm
multipathing, or run GFS on gnbd server machines. To set up dm
multipathing over gnbd, all gnbds involved must run with caching
disabled. Data corruption will occur if the GNBD devices are
run with caching. Any device that is exported without the -c
option can also be used locally, but you must access the device
directly. You MUST NOT use gnbd_import to import devices
exported from the same machine.
Specify the device to export as a GNBD. This option is used
with -e. pathname may be either a block device or a regular
file. Usually block devices are used, because this increases
Export a device as a GNBD with the Device name gnbdname. You
must also specify the pathname of the device with the -d option.
Once a GNBD has been exported, clients can import it with
Print the usage information.
List all exported GNBDs and kgnbd_portd server information. The
listing contains each server’s number (which is only for
internal use), its Device name, the pathname of the device that
is being exported, it’s size in 512 byte sectors, and
information on whether or not it is cached, and if not, what
it’s timeout is.
This option allows you to unexport gnbd devices, even if they
are still in use. When an agent other than fence_gnbd is used
to fence gnbd client nodes, occasionally gnbd server threads are
not correctly cleaned up. This causes no performance issues.
However, the affected gnbd devices cannot be unexported. In
this case, using the -O option with either -r or -R will allow
you to unexport the GNBD devices. WARNING: Make sure that no
clients have the GNBD imported before using this option.
export the server in readonly mode.
Only prints out error messages.
-R Remove All.
Remove all exported GNBDs.
Remove named GNBD(s).
Set the exported GNBD to timeout mode This option is used with
-p. This is the default for uncached GNBDs. For cached GNBDs,
the default is wait mode (For GFS versions up through 5.2, all
GNBDs were in wait mode). In wait mode, if the connection to
the server is lost, the gnbd client waits for the connection to
be reestablished, and then resends all the pending requests. In
timeout mode, if the connection cannot be reestablished or if
the gnbd client does not receive a response from the server
within the timeout period, the gnbd client returns all pending
and future requests as failures until the imported GNBD is
closed. The default timeout period is 60 seconds. Timeout mode
is necessary for failover to work with dm multipathing over
Increase the verbosity of the output. This option is the most
useful with -l. If it is used along with -l, an extended list
of information on each exported device will be printed.
-V Version information.
Print out version information.