Configuring iSCSI interface and offload support¶
Compute supports open-iscsi iSCSI interfaces for offload cards. Offload
hardware must be present and configured on every compute node where offload is
desired. Once an open-iscsi interface is configured, the iface name
(iface.iscsi_ifacename
) should be passed to libvirt via the iscsi_iface
parameter for use. All iSCSI sessions will be bound to this iSCSI interface.
Currently supported transports (iface.transport_name
) are be2iscsi
,
bnx2i
, cxgb3i
, cxgb4i
, qla4xxx
, ocs
. Configuration changes
are required on the compute node only.
iSER is supported using the separate iSER LibvirtISERVolumeDriver and will be
rejected if used via the iscsi_iface
parameter.
iSCSI iface configuration¶
Note the distinction between the transport name (
iface.transport_name
) and iface name (iface.iscsi_ifacename
). The actual iface name must be specified via the iscsi_iface parameter to libvirt for offload to work.The default name for an iSCSI iface (open-iscsi parameter
iface.iscsi_ifacename
) is in the format transport_name.hwaddress when generated byiscsiadm
.iscsiadm
can be used to view and generate current iface configuration. Every network interface that supports an open-iscsi transport can have one or more iscsi ifaces associated with it. If no ifaces have been configured for a network interface supported by an open-iscsi transport, this command will create a default iface configuration for that network interface. For example :# iscsiadm -m iface default tcp,<empty>,<empty>,<empty>,<empty> iser iser,<empty>,<empty>,<empty>,<empty> bnx2i.00:05:b5:d2:a0:c2 bnx2i,00:05:b5:d2:a0:c2,5.10.10.20,<empty>,<empty>
The output is in the format:
iface_name transport_name,hwaddress,ipaddress,net_ifacename,initiatorname
Individual iface configuration can be viewed via
# iscsiadm -m iface -I IFACE_NAME # BEGIN RECORD 2.0-873 iface.iscsi_ifacename = cxgb4i.00:07:43:28:b2:58 iface.net_ifacename = <empty> iface.ipaddress = 102.50.50.80 iface.hwaddress = 00:07:43:28:b2:58 iface.transport_name = cxgb4i iface.initiatorname = <empty> # END RECORD
Configuration can be updated as desired via
# iscsiadm -m iface-I IFACE_NAME--op=update -n iface.SETTING -v VALUE
All iface configurations need a minimum of
iface.iface_name
,iface.transport_name
andiface.hwaddress
to be correctly configured to work. Some transports may requireiface.ipaddress
andiface.net_ifacename
as well to bind correctly.Detailed configuration instructions can be found at: https://github.com/open-iscsi/open-iscsi/blob/master/README