Chapter 1. Introduction
Chelsio T5 iSCSI PDU Offload Target with SCST support for Linux 5
1.Introduction
Thank you for choosing Chelsio Unified Wire adapters. These high speed, single chip, single
firmware cards provide enterprises and data centers with high performance solutions for various
Network and Storage related requirements.
The Terminator 5 (T5) is Chelsio’s next generation of highly integrated, hyper-virtualized
40/10GbE controllers. The T5 is built around a programmable protocol-processing engine, with
full offload of a complete Unified Wire solution comprising NIC, TOE, iWARP RDMA, ISCSI,
FCoE and NAT support. It scales true 40Gb line rate operation from a single TCP connection to
thousands of connections, and allows simultaneous low latency and high bandwidth operation
thanks to multiple physical channels through the ASIC.
The adapters can fully offload TCP, UDP, iSCSI, iWARP and FCoE over a single Unified Wire.
The adapters also fully support SR-IOV, EVB/VNTag, DCB, Traffic Management and Filtering.
Ideal for all data, storage and high performance clustering applications, the adapters enable a
unified fabric over a single wire by simultaneously running all unmodified IP sockets, Fibre
Channel and InfiniBand applications over Ethernet at line rate.
Designed for deployment in virtualized data centers, cloud service installations and high
performance computing environments, Chelsio adapters bring a new level of performance
metrics and functional capabilities to the computer networking industry.
This guide describes how to install, use and configure iSCSI PDU Offload Target software with
SCST support (known as ‘iSCSI Target driver’, ‘iSCSI Target software’, ‘driver’ or ‘software,
henceforth) for use as a key element in your iSCSI SAN. SCST is an easy-to-use and scalable
in-kernel SCSI target implementation in Linux, which provides advanced functionality, high
performance and reliability. The target driver acts as a SCSI target for remote SCSI initiators,
i.e. accepts remote connections, passes incoming SCSI requests to SCST and sends SCSI
responses from SCST back to their originators. Currently Passthrough, FILEIO and BLOCKIO
modes are supported.
The iSCSI Target software runs on Linux-based systems that use Chelsio or non-Chelsio based
Ethernet adapters. However, to guarantee highest performance, Chelsio recommends using
Chelsio adapters. Chelsio’s adapters include offerings that range from stateless offload
adapters (regular NIC) to the full line of TCP/IP Offload Engine (TOE) adapters.
The software implements RFC 3720, the iSCSI standard of the IETF. The software has been
fully tested for compliance to that RFC and others and it has been exhaustively tested for
interoperability with the major iSCSI vendors.
The software implements most of the iSCSI protocol in software running in kernel mode on the
host with the remaining portion, which consists of the entire fast data path, in hardware when
used with Chelsio’s TOE adapters. When standard NIC Adapters are used the entire iSCSI
protocol is executed in software.
