fence_gnbd(8)fence_gnbd(8)NAMEfence_gnbd - I/O Fencing agent for GNBD-based GFS clusters
SYNOPSISfence_gnbd [OPTION]...
DESCRIPTIONfence_gnbd is an I/O Fencing agent used when GFS is accessed through
GNBD. It uses the gnbd_import program and tells a GNBD server to
ignore I/O from a specified machine.
fence_gnbd accepts options on the command line as well as from stdin.
fence_node sends the options through stdin when it execs the agent.
fence_gnbd can be run by itself with command line options which is use‐
ful for testing.
OPTIONS-h Print out a help message describing available options, then
exit.
-m Selects multipath style fencing. With multipath style fencing,
if fence_gnbd cannot contact the kgnbd_portd process on the gnbd
server node, it will fence that server node. This is necessary
to insure that there is no way for the fenced client to access
the storage through that server. WARNING: Multipath style fenc‐
ing must be used on a node if it is using pool multipathing with
GNBD devices.
-q quiet mode, no output.
-s node
gnbd client machine to fence.
-t node
server machine to fence the gnbd client from. If this option is
not given, the specified gnbd client node will be fenced from
all gnbd server nodes that have GNBDs imported by the machine
running fence_gnbd. Using the -t option is strongly recom‐
mended. The -t option may be used multiple times to fence a
client from multiple servers.
-V Print out a version message, then exit.
STDIN PARAMETERS
agent = < param >
This option is used by fence_node(8) and is ignored by
fence_gnbd.
ipaddr = < clustername >
The cluster name of the node to be fenced (required) NOTE: This
parameter no longer allows the IP address of the node to be
used. This parameter is deprecated. Please use nodename instead.
nodename = < clustername >
The cluster name of the node to be fenced (required)
servers = < hostname [ hostname ... ] >
A whitespace seperated list of the servers to fence the client
from, in either IP address or hostname form.
option = multipath
Select multipath style fencing. WARNING: When multipath style
fencing is used, if the kgnbd_portd process of a gnbd server
node cannot be contacted, it is fenced as well, using its appro‐
priate fencig method. This means that when a client is fenced,
any node listed as its server that does not have the gnbd_serv
module loaded (which starts kgnbd_portd) will also be fenced.
retrys = < param >
Number of times to retry connecting to the server after a failed
attempt, before the server is fenced. This parameter is only
valid when used with multipath style fencing (see above). The
default is 3.
wait_time = < param >
length of time, in seconds, to wait between retrys. This parame‐
ter is only valid when used with multipath sytle fencing (see
above). The default is 2.
SEE ALSOfence(8), fenced(8), gnbd_import(8)fence_gnbd(8)
