IBM Flex Systems Interconnect Fabric

IBM Flex System Interconnect Fabric 1

I B M ®

IBM Flex System Interconnect FabricIBM Redbooks Solution Guide

IBM® Flex System® Interconnect Fabric offers a solid foundation of compute, network, storage, and software resources in a Flex System point of delivery (POD). The entire POD integrates a seamless network fabric for compute node and storage under single IP management, and it attaches to the upstream data center network as a loop-free Layer 2 network fabric with a single Ethernet uplink connection or aggregation group to each layer 2 network, as shown in the following figure. The POD requires only network provisioning for uplink connections to a data center network, downlink connections to compute nodes, and storage connections to storage nodes.

Figure 1. IBM Flex System Interconnect Fabric

Did you know?

Flex System Interconnect Fabric reduces communication latency and improves application response time with support for local switching within the chassis, and it reduces networking management complexity without compromising performance by lowering the number of devices that must be managed by 95% (managing one device instead of 20).

Flex System Interconnect Fabric simplifies POD integration into an upstream network by transparently interconnecting hosts to a data center network and representing the POD as a large compute element isolating the POD's internal connectivity topology and protocols from the rest of the network.


Business value

The Flex System Interconnect Fabric solution offers the following benefits:

Network simplification

Provisions a seamless network fabric for compute node and storage connectivity in the data ocenter.

Offers a loop-free network fabric without STP complexity for fast network convergence.o

Minimizes network latency by local Layer 2 switching at every interconnect component and ominimizes loss of data during network failover within the fabric.

Converges Ethernet for lossless storage traffic.o

Integrates FCF to provide end-to-end FCoE storage functionality within the POD without needing oan expensive Fibre Channel switch.

Supports single fabric mode topology and dual fabric mode topology.o

Management simplification

Offers high availability with master and backup Top of Rack (TOR) switches in the fabric and ohitless upgrade with no downtime for services.

Minimizes managed network elements with single point of management of the entire fabric at the omaster TOR switch.

Establishes a clear administrative boundary in data center by pushing traditional networking oconfiguration outside of the POD.

Integrates physical and virtual infrastructure management for compute, network, storage, and osoftware elements.

Storage integration

Simplifies integration of storage and storage virtualization with IBM Flex System V7000 Storage oNode.

Provides access to an external SAN storage infrastructure, such as IBM Storwize® V7000.o

Scalable POD design

Enables the size of the POD to grow without adding management complexity. o

Adds chassis resources up to the maximum configuration under the single IP management of the oPOD.


Solution overview

The Flex System Interconnect Fabric solution has the following key elements:

Hardware elements

IBM RackSwitch™ G8264CS (10/40 GbE, 4/8 Gb FC uplink) as Aggregation

Flex System Fabric SI4093 System Interconnect Module (10 GbE to compute node) as Access

Embedded VFA, CN4054, or CN4058 adapters

Flex System V7000 Storage Node or Storwize V7000

Software elements

Single IP managed multi-rack cluster (hDFP)

Automated rolling (staggered) upgrades of individual switches

Per-server link redundancy (LAG or active/passive teaming)

Dynamic bandwidth within and out of the POD

Multi-rack Flex System Interconnect mode

Integration of UFP and IBM VMready®

Management elements

IBM System Networking Switch Center management application (fabric management)

Flex System Manager configuration patterns (compute node NIC configuration)

Flex System Interconnect Fabric supports the following networking software features:

Single IP managed cluster

1024 VLANs

Layer 2 loop-free solution with upstream data center core

FCoE and native Fibre Channel support

Eight unicast traffic classes and four multicast traffic classes with configurable bandwidth

Priority flow control for maximum of two priorities

UFP virtual port support (four per 10 Gb physical port)

VMready

VMready/FCoE interoperability with UFP

Tunneled VLAN domain (Q-in-Q) for multi-tenant customer VLAN isolation

IGMPv2 Snooping for multicast optimization

256 access lists and 128 VLAN maps for security and rate limiting policing

Static/LACP portchannel

L2 Failover (Manual Monitor - MMON)

Hotlinks

VLAN-based load distribution in hotlinks (for active/active connectivity with non-vPC uplink)

Industry-standard command-line interface (isCLI)

SNMP

IPv6 support for management

Staggered upgrade

HiGig trunk

Local preference for unicast traffic

Port mirroring


Solution architecture

The SI4093, an embedded module, has 42 10GBASE-KR ports that connect to the compute nodes in the Flex System chassis through the midplane; there are three 10 Gb ports that connect to each of the 14 slots in the chassis.

The G8264CS has 12 Omni ports, which can be configured to operate either as 4/8 Gb Fibre Channel ports or as 10 Gb Ethernet ports. It also has an internal hardware module with a dedicated ASIC, which provides the FC gateway functionality (FCF and NPV).

Both the SI4093 and G8264CS have PHY interfaces for SFP+ transceivers and QSFP+ transceivers that can run either as a single 40 Gb port or as a set of four 10 Gb ports using a breakout cable. The interconnection between the SI4093 modules and the G8264CS aggregation switches is configured to run over standard 10 Gb connections. Similar connections are used between the pair of G8264CS aggregation switches, although it is possible to use 40 Gb links here. A Broadcom proprietary protocol, hDFP, is used over these links, which are referred to in the diagrams in this solution guide as HiGig links. This protocol carries proprietary control information and the content of the network traffic, and it enables the multiple switching processors in the different switches to operate as though they are part of a single switch.

In the Flex System Interconnect Fabric, one of the G8264CS aggregation switches is the master and the other is a backup for purposes of managing the environment. If the master switch fails, the backup G8264CS aggregation switch takes on this task.

The links between switching elements in an Flex System Interconnect Fabric configuration are known as Fabric Ports. Fabric Ports must be explicitly configured on both sides, and assigned to a reserved VLAN. If two or more Fabric Ports are connected between the same two devices, then all of them are used as the aggregated link that forms automatically.


The Flex System Interconnect Fabric solution architecture is shown in the following figure.

Figure 2. Flex System Interconnect Fabric solution architecture

A typical Flex System Interconnect Fabric configuration uses four 10 Gb ports as Fabric Ports from each SI4093 module, two ports to each of the aggregation switches (up to 1:3.5 oversubscription with 2-port Embedded VFAs or up to 1:7 oversubscription with 4-port CNAs). The maximum of nine chassis, with a total of eighteen SI4093 modules, use 36 ports on each of the G8264CS aggregation switches. It is possible to use additional ports from the SI4093 modules to the aggregation switches if there are ports available, up to a total of eight. All external ports on the SI4093 modules are configured as Fabric Ports, and this cannot be changed.

Fabric Ports do not need additional configuration other than what identifies them as Fabric Ports. They carry the hDFP proprietary protocol, which allows them to forward control information and substantive data traffic from one switching element to another within the Flex System Interconnect Fabric environment. G8264CS ports that are not configured as Fabric Ports can be used as uplink ports. (Omni ports cannot be configured as Fabric Ports.)

Uplink ports are used for connecting the Flex System Interconnect Fabric POD to the upstream data network (standard ports and Omni ports) and to the storage networks (Omni ports only).


Flex System Interconnect Fabric is formed on its own by establishing HiGig links using the configured Fabric Ports. All HiGig links are active, and they carry network traffic. The actual traffic flow path between the different members in the fabric is established when a member joins the fabric or other topology change occurs. The data path should be balanced as well as possible.

Usage scenarios

The Flex System Interconnect Fabric can be VLAN-aware or VLAN-agnostic depending on specific client requirements.

In VLAN-aware mode (shown in the following figure), client VLAN isolation is extended to the fabric by filtering and forwarding VLAN tagged frames that are based on the client VLAN tag, and client VLANs from the upstream network are configured within the Flex System Interconnect Fabric and on virtual switches (vSwitches) in hypervisors.

Figure 3. VLAN-aware Flex System Interconnect Fabric


In VLAN-agnostic mode (shown in the following figure), the Flex System Interconnect Fabric transparently forwards VLAN tagged frames without filtering on the client VLAN tag, providing an end host view to the upstream network, where client VLANs are configured on vSwitches only. This is achieved by the use of a Q-in-Q type operation to hide user VLANs from the switch fabric in the POD so that the Flex System Interconnect Fabric acts as more of a port aggregator and is user VLAN-independent.

The VLAN-agnostic mode of the Flex System Interconnect Fabric can be implemented through the tagpvid-ingress feature or UFP vPort tunnel mode. If no storage access is required for the compute nodes in the POD, then the tagpvid-ingress mode is the simplest way to configure the fabric. However, if you want to use FCoE storage, you cannot use the tagpvid-ingress feature and must switch to UFP tunnel mode.

Figure 4. VLAN-agnostic Flex System Interconnect Fabric

All VMs that are connected to the same client VLAN can communicate with each other within the POD and with other endpoints that are attached to this VLAN in the upstream network. VMs and endpoints that are connected to different VLANs cannot communicate with each other in the Layer 2 network.

vSwitches are connected to Flex System Interconnect Fabric through a teamed NIC interface that is configured on the compute node. The compute node’s CNA NIC ports (either physical (pNIC) or virtual (UFP vPort) ports) are configured in a load-balancing pair (static or LACP aggregation) using the hypervisor’s teaming/bonding feature. Respective compute node-facing ports on the SI4093 modules are also configured for static or dynamic aggregation, and VLAN tagging (802.1Q) is enabled on the aggregated link.


If the upstream network supports distributed (also called virtual) link aggregation, this type of aggregation can be used to connect Flex System Interconnect Fabric to the core. Flex System Interconnect Fabric sees the upstream network as one logical switch, and the upstream network sees Flex System Interconnect Fabric as one logical switch. A single aggregated port channel (static or dynamic) is configured between these two logical switches using all connected uplinks, and all these links in the aggregation carry traffic from all client VLANs.

If virtual link aggregation is not supported on the upstream network switches (that is, the upstream network operates in a standard STP domain), then Hot Link interfaces are used. Flex System Interconnect Fabric sees the upstream network as two separate switches, and the upstream network sees Flex System Interconnect Fabric as one logical switch.

This logical switch is connected to the upstream switches using two aggregated port channels (static or dynamic):

One port channel is configured between the first upstream switch and the Flex System Interconnect

Fabric logical switch.

Another port channel is configured between the second upstream switch and the Flex System

Interconnect Fabric logical switch.

One port channel is designated as the master hot link, and the second port channel is configured as the backup hot link. The master port channel carries traffic from all client VLANs, and the backup port channel is in the blocking state. If there is a master port channel failure, the backup port channel becomes active and all traffic flows through it. The downside of this approach is that only half of the available uplink bandwidth is used. Flex System Interconnect Fabric supports VLAN load distribution over Hot Links to maximize bandwidth usage, and both hot links are masters and backups for different VLANs at the same time.

Integration

The Flex System Interconnect Fabric converged network design enables shared access to the full capabilities of the FCoE-based V7000 Storage Node and Storwize V7000 storage systems while simultaneously providing connectivity to the client’s enterprise FC SAN storage environment.

Flex System Interconnect Fabric introduces a new storage fabric capability that is called Hybrid Fabric, in which there are two types of SANs, internal and external, on separate SAN fabrics. The internal SAN is used for the POD-wide V7000 Storage Node or Storwize V7000 connectivity in Full Fabric mode, and the external SAN is used for the data center-wide storage connectivity in NPV Gateway mode. Both internal and external SANs are dual-fabric SANs, and the total number of fabrics in the hybrid storage configuration is four.

Hybrid mode requires dual initiators per compute node connection to each SI4093 module so that each initiator can discover one FC fabric. Each initiator can communicate only with one FCF VLAN and FC fabric. The 4-port and 8-port CNAs offer the required number of ports to support dual switch path storage access. Dual-port CNAs (such as embedded VFA LOM) can also be used for storage connectivity, but only one type of dual-fabric SAN can be used, either internal or external but not both. Each HBA port on the CNA that is installed in the compute node is connected to the dedicated fabric. Path redundancy is provided with the usage of MPIO software that is installed on the compute node (in the bare-metal operating system or in the hypervisor).


The hybrid storage configuration, which uses both internal IBM Flex System V7000 Storage Node and the client's external storage, is shown in the following figure.

Figure 5. Flex System Interconnect Fabric storage integration

The compute node’s HBA ports 1 and 2 are used to connect to the internal storage in the Full Fabric mode, and HBA ports 3 and 4 provide connectivity to the external FC SAN storage in the NPV mode.

Supported platforms

Flex System Interconnect Fabric is supported by the following network devices:

IBM RackSwitch G8264CS

IBM Flex System Fabric SI4093 System Interconnect Module

Note: Two G8264CS switches and from two to 18 SI4093 modules are supported in a POD. G8264CS switches and SI4093 modules in a POD run a special Flex System Interconnect Fabric software image of IBM Networking OS V7.8 or later.


The following adapters are supported:

IBM Flex System Embedded Virtual Fabric LOM

IBM Flex System CN4054/CN4054R 10Gb Virtual Fabric Adapter

IBM Flex System CN4058 10Gb Converged Adapter

Ordering information

The following table shows example bill of materials (BOM) for a 3-chassis Flex System Interconnect Fabric POD consisting of the following items:

Six SI4093 modules

Two G8264CS switches with the required SFP+ DAC cables

Required rack and PDU infrastructure

Optional IBM System Networking Switch Center management application

Note: Up to 42 half-wide or 84 high-density compute nodes can be used in this example, but they are not included in the table.

Table 1. Ordering part numbers

Part number Description Quantity

Rack and PDU infrastructure

93604PX IBM 42U 1200mm Deep Dynamic Rack 1

46M4143 IBM 0U 12 C19/12 C13 32A 3 Phase PDU 2

25R5559 1U Quick Install Filler Panel Kit 2

Top of Rack switches

7309DRX IBM System Networking RackSwitch G8264CS (Rear-to-Front) 2

90Y9430 3m IBM Passive DAC SFP+ Cable 16

90Y9427 1m IBM Passive DAC SFP+ Cable 10

Flex System Enterprise Chassis with SI4093 modules

8721A1G IBM Flex System Enterprise Chassis with 2x2500W PSU 3

43W9049 IBM Flex System Enterprise Chassis 2500W Power Module 12

95Y3313 IBM Flex System Fabric SI4093 System Interconnect Module 6

68Y7030 IBM Flex System Chassis Management Module 3

43W9078 IBM Flex System Enterprise Chassis 80mm Fan Module Pair 6

Management application (optional)

00AE226 IBM System Networking Switch Center, per installation with 1-year software subscription and support for 20 switches

1

Note: Cables or SFP+ modules for the upstream network connectivity are not included.


Related information

For more information, see the following documents:

IBM Flex System Interconnect Fabric: Technical Overview and Planning Considerations, REDP-5106

http://www.redbooks.ibm.com/abstracts/redp5106.html

NIC Virtualization on IBM Flex System, SG24-8223

http://www.redbooks.ibm.com/abstracts/sg248223.html

IBM Flex System Fabric SI4093 System Interconnect Module Product Guide

http://www.redbooks.ibm.com/abstracts/tips1045.html

IBM RackSwitch G8264CS Product Guide


IBM Flex System Interconnect Fabric offering page:

http://www-03.ibm.com/systems/flex/networking/bto/fabric/interconnect_fabric/index.html

http://www.redbooks.ibm.com/abstracts/redp5106.html

http://www.redbooks.ibm.com/abstracts/sg248223.html



http://www-03.ibm.com/systems/flex/networking/bto/fabric/interconnect_fabric/index.html


NoticesThis information was developed for products and services offered in the U.S.A.

IBM may not offer the products, services, or features discussed in this document in other countries. Consult your local IBM representative for information on the products and services currently available in your area. Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM product, program, or service may be used. Any functionally equivalent product, program, or service that does not infringe any IBM intellectual property right may be used instead. However, it is the user's responsibility to evaluate and verify the operation of any non-IBM product, program, or service. IBM may have patents or pending patent applications covering subject matter described in this document. The furnishing of this document does not give you any license to these patents. You can send license inquiries, in writing, to:

IBM Director of Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785 U.S.A.

The following paragraph does not apply to the United Kingdom or any other country where such provisions are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION PROVIDES THIS PUBLICATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer of express or implied warranties in certain transactions, therefore, this statement may not apply to you. This information could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein; these changes will be incorporated in new editions of the publication. IBM may make improvements and/or changes in the product(s) and/or the program(s) described in this publication at any time without notice.

Any references in this information to non-IBM Web sites are provided for convenience only and do not in any manner serve as an endorsement of those Web sites. The materials at those Web sites are not part of the materials for this IBM product and use of those Web sites is at your own risk.IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring any obligation to you. Information concerning non-IBM products was obtained from the suppliers of those products, their published announcements or other publicly available sources. IBM has not tested those products and cannot confirm the accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on the capabilities of non-IBM products should be addressed to the suppliers of those products. This information contains examples of data and reports used in daily business operations. To illustrate them as completely as possible, the examples include the names of individuals, companies, brands, and products. All of these names are fictitious and any similarity to the names and addresses used by an actual business enterprise is entirely coincidental.

Any performance data contained herein was determined in a controlled environment. Therefore, the results obtained in other operating environments may vary significantly. Some measurements may have been made on development-level systems and there is no guarantee that these measurements will be the same on generally available systems. Furthermore, some measurement may have been estimated through extrapolation. Actual results may vary. Users of this document should verify the applicable data for their specific environment.

COPYRIGHT LICENSE:

This information contains sample application programs in source language, which illustrate programming techniques on various operating platforms. You may copy, modify, and distribute these sample programs in any form without payment to IBM, for the purposes of developing, using, marketing or distributing application programs conforming to the application programming interface for the operating platform for which the sample programs are written. These examples have not been thoroughly tested under all conditions. IBM, therefore, cannot guarantee or imply reliability, serviceability, or function of these programs.

© Copyright International Business Machines Corporation 2014. All rights reserved.Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted byGSA ADP Schedule Contract with IBM Corp.


This document was created or updated on May 18, 2014.

Send us your comments in one of the following ways:Use the online Contact us review form found at:

ibm.com/redbooksSend your comments in an e-mail to:

[email protected] your comments to:

IBM Corporation, International Technical Support OrganizationDept. HYTD Mail Station P0992455 South RoadPoughkeepsie, NY 12601-5400 U.S.A.

This document is available online at http://www.ibm.com/redbooks/abstracts/tips1183.html .

TrademarksIBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both. These and other IBM trademarked terms are marked on their first occurrence in this information with the appropriate symbol (® or ™), indicating US registered or common law trademarks owned by IBM at the time this information was published. Such trademarks may also be registered or common law trademarks in other countries. A current list of IBM trademarks is available on the web at http://www.ibm.com/legal/copytrade.shtml.

The following terms are trademarks of the International Business Machines Corporation in the United States, other countries, or both:

IBM®IBM Flex System®RackSwitch™Redbooks (logo)®Storwize®VMready®

Other company, product, or service names may be trademarks or service marks of others.

mailto:[email protected]

http://www.ibm.com/redbooks/abstracts/tips1183.html

http://www.ibm.com/legal/copytrade.shtml.

IBM Flex Systems Interconnect Fabric

Technology

seamless network fabric

entire fabric

loopfree network fabric

network simplification

network latency

upstream network

network provisioning

network failover