Red Hat ENTERPRISE LINUX 4 - GLOBLAL NETWORK BLOCK DEVICE Using Instructions

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Examples7If two GNBD devices are not exporting the same underlying device, but are given thesame UID, data corruption will occur.-U CommandGets the UID command. The UID command is a command the gnbd_export command will runto get a Universal Identifier for the exported device. The UID is necessary to use device-mappermultipath with GNBD. The command must use the full path of any executeable that you wish torun. A command can contain the %M, %m or %n escape sequences. %M will be expanded to themajor number of the exported device, %m will be expaned to the minor number of the exporteddevice, and %n will be expanded to the sysfs name for the device. If no command is given,GNBD will use the default command /usr/sbin/gnbd_get_uid. This command will work formost SCSI devices.ExamplesThis example is for a GNBD server configured with GNBD multipath. It exports device /dev/sdc2 asGNBD gamma. Cache is disabled by default.gnbd_export -d /dev/sdc2 -e gamma -UThis example is for a GNBD server not configured with GNBD multipath. It exports device /dev/sdb2as GNBD delta with cache enabled.gnbd_export -d /dev/sdb1 -e delta -cThis example exports device /dev/sdb2 as GNBD delta with cache enabled.gnbd_export -d /dev/sdb2 -e delta -c3.2. Importing a GNBD on a ClientThe gnbd.ko kernel module must be loaded on a node before it can import GNBDs. When GNBDsare imported, device nodes are created for them in /dev/gnbd/ with the name assigned when theywere exported.Usagegnbd_import -i ServerServerSpecifies a GNBD server by hostname or IP address from which to import GNBDs. All GNBDsexported from the server are imported on the client running this command.