Red Hat GNBD WITH GLOBAL FILE SYSTEM 4.7 Configuration And Administration Manual page 17

-uuid
Manually sets the Universal Identifier for an exported device. This option is used with
The UID is used by device-mapper multipath to determine which devices belong in a
multipath map. A device must have a UID to be multipathed. However, for most SCSI
devices the default Get UID command,
appropriate value.
Note
The UID refers to the device being exported, not the GNBD itself. The UIDs of
two GNBD devices should be equal, only if they are exporting the same
underlying device. This means that both GNBD servers are connected to the
same physical device.
Warning
This option should only be used for exporting shared storage devices, when the
-Ucommand
devices. If two GNBD devices are not exporting the same underlying device, but
are given the same UID, data corruption will occur.
-UCommand
Gets the UID command. The UID command is a command the
run to get a Universal Identifier for the exported device. The UID is necessary to use
device-mapper multipath with GNBD. The command must use the full path of any
executeable that you wish to run. A command can contain the %M, %m or %n escape
sequences. %M will be expanded to the major number of the exported device, %m will be
expaned to the minor number of the exported device, and %n will be expanded to the
name for the device. If no command is given, GNBD will use the default command
/usr/sbin/gnbd_get_uid
Examples
This example is for a GNBD server configured with GNBD multipath. It exports device
as GNBD
/dev/sdc2 gamma
gnbd_export -d /dev/sdc2 -e gamma -U
This example is for a GNBD server not configured with GNBD multipath. It exports device
as GNBD
/dev/sdb2 delta
/usr/sbin/gnbd_get_uid
option does not work. This should almost never happen for SCSI
. This command will work for most SCSI devices.
. Cache is disabled by default.
with cache enabled.
Examples
, will return an
command will
gnbd_export
.
-e
sysfs
7