Installation guide
Configuring iSCSI Offload and Interface Binding
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iscsiadm -m discovery -t discovery_type -p target_IP:port -o delete
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Here, discovery_type can be either sendtargets, isns, or fw.
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There are two ways to reconfigure discovery record settings:
• Edit the /etc/iscsi/iscsid.conf file directly prior to performing a discovery. Discovery settings
use the prefix discovery; to view them, run:
iscsiadm -m discovery -t discovery_type -p target_IP:port
• Alternatively, iscsiadm can also be used to directly change discovery record settings, as in:
iscsiadm -m discovery -t discovery_type -p target_IP:port -o update -n
setting -v %value
Refer to man iscsiadm for more information on available settings and valid values for each.
After configuring discovery settings, any subsequent attempts to discover new targets will use the new
settings. Refer to Section 21.12, “ Scanning iSCSI Interconnects” for details on how to scan for new
iSCSI targets.
For more information on configuring iSCSI target discovery, refer to the man pages of iscsiadm
and iscsid. The /etc/iscsi/iscsid.conf file also contains examples on proper configuration
syntax.
21.11. Configuring iSCSI Offload and Interface Binding
This chapter describes how to set up iSCSI interfaces in order to bind a session to a NIC port when
using software iSCSI. It also describes how to set up interfaces for use with network devices that
support offloading; namely, devices from Chelsio, Broadcom and ServerEngines.
The network subsystem can be configured to determine the path/NIC that iSCSI interfaces should use
for binding. For example, if portals and NICs are set up on different subnets, then it is not necessary to
manually configure iSCSI interfaces for binding.
Before attempting to configure an iSCSI interface for binding, run the following command first:
ping -I ethX target_IP
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If ping fails, then you will not be able to bind a session to a NIC. If this is the case, check the network
settings first.
21.11.1. Viewing Available iface Configurations
Red Hat Enterprise Linux 5.5 supports iSCSI offload and interface binding for the following iSCSI
initiator implementations:
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Software iSCSI — like the scsi_tcp and ib_iser modules, this stack allocates an iSCSI host
instance (i.e. scsi_host) per session, with a single connection per session. As a result, /sys/
class_scsi_host and /proc/scsi will report a scsi_host for each connection/session you
are logged into.
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The target_IP and port variables refer to the IP address and port combination of a target/portal, respectively. For more
information, refer to Section 21.2.1, “iSCSI API” and Section 21.12, “ Scanning iSCSI Interconnects”.
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For details on different types of discovery, refer to the DISCOVERY TYPES section of man iscsiadm.