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FICON MIGRATION:Save Money &ImprovePerformance in YourMainframeInfrastructureBY SEAN SEITZ & STEVE GUENDERT

Numerous articles

and white papers

have been written on

the performance

advantages of Fibre

Connection (FICON) over

Enterprise Systems

Connection (ESCON).

Clearly, FICON is a major

improvement over ESCON;

data centers that have

migrated from ESCON to

FICON have seen

improved response >

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times and performance. Yet, only an esti-mated 20 to 25 percent of existingESCON customers have migrated toFICON. A major factor in delaying amigration to FICON is the initial cost ofentry, including the purchase of newhardware and infrastructure. Anotherfactor was the lack of native FICON stor-age devices when FICON was initiallyannounced as generally available. Thishas led to many prospective FICON cus-tomers having to do “rolling upgrades” ofstorage devices, which has furtherincreased the cost of migrating.Mainframe users find it difficult to rec-ognize and quantify cost savings associat-ed with eliminating some ESCONinfrastructure and leveraging other exist-ing ESCON hardware by attaching it tothe FICON network.

This article examines how migrat-ing from ESCON to FICON savesmoney and, thanks to emerging tech-nology, protects your investment inESCON-attached storage as you moveto FICON. We’ll consider how thetechnology and performance improve-ments inherent in FICON help yousave money on your mainframe infra-structure.

Technical Benefits of FICON Over ESCONFICON has proved to be a major

improvement over ESCON since itsinception in 1998. Today, the benefit iseven clearer with the advent of 2Gbpstechnology (4Gbps is on the way), cas-caded FICON, and FICON-FibreChannel Protocol (FCP) intermix. Wewon’t go into detail on these here, butyou can refer to the list of reference pub-lications at the end of this article formore detailed information.

Technical advantages that yield busi-ness or cost advantages include:

• FICON’s greater addressing limits• Improved bandwidth and I/O capabil-

ities• Improved distance• Protocol improvements that accelerate

response times.

We’ll discuss how this translates tocost savings with respect to DASD envi-ronments, tape/virtual tape environ-ments, disaster recovery applications, thehost, and the physical infrastructure.

Business Benefits of FICON There are six primary business bene-

fits realized when migrating fromESCON to FICON:

1. FICON’s advantages enhance overallperformance in the mainframe envi-ronment, meaning more work can bedone faster. In the financial sector,the speed in which trades can occur isdirectly tied to a firm’s ability to gen-erate revenue. Moving to FICON cantranslate directly to cost savings andprofit gains.

2. FICON enhances enterprise resilien-cy and disaster recovery planningbased on the extended distances theprotocol supports. FICON’s band-width capability enables faster recov-ery over those distances.

3. FICON enhances a business’s accessi-bility to data with its higher address-ing limitations, which translates tomore disk volumes being accessibleto a given channel path.

4. The FICON protocol has room forgrowth (16,000 addresses supportedtoday with available growth to65,000 addresses). This helps you bet-ter prepare for internal growth orother changes. FICON also allows formixed workloads on the same chan-nel (disk and tape).

5. The cumulative advantages ofFICON can help you consolidate theIT infrastructure in terms of themainframe footprint and storageenvironments, and even total num-ber of data centers.

6. FICON and FCP intermix helps youcapitalize on IT budget dollars target-ed for storage networking infrastruc-ture. z/OS and Linux can now besupported on the same mainframefootprint and FICON and open sys-tems Storage Area Networks (SANs)can leverage the same directors. Usinga common infrastructure for all stor-age connectivity, both open systemsand mainframe, can help your organ-ization improve ROI and TCO.

You need to weigh these business bene-fits against the following costs of movingfrom ESCON to FICON:

• FICON cabling: You’ll need to put in anew cabling infrastructure (9/125micron long-wave, single-mode fiber isrecommended) or leverage your exist-ing ESCON cabling via the addition ofMode Conditioning Patch (MCP)cables. Use of MCP cables will restrictyou to a 1Gbps FICON network, soinvesting in single-mode infrastructureis strongly recommended. Either alter-Figure 1: ESCON/FICON Comparison

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native is a cost to consider.• FICON DASD: Most businesses that

migrate to FICON don’t do so just forthe connectivity advantages. Generally,there’s a more significant driving fac-tor. Often, the key driver is that olderESCON DASD is coming off lease, or amaintenance contract is nearing expira-tion. These businesses typically won’tinvest in new DASD array(s) rightaway and will continue to use ESCON.

• FICON tape drives/libraries/virtualtape: Similar to DASD above.

• FICON directors: Larger mainframeenvironments moving to FICON willwant to purchase FICON directors toreplace their ESCON directors. Directattachment of FICON only makessense for the smallest of FICON envi-ronments (i.e., one host, one or twoDASD frames). FICON directors canbe a significant cost. However, nowthat all four major switch/directorvendors (CNT, Cisco, McDATA, andBrocade) have IBM support for

FICON, the cost of FICON directorshas come down significantly in the pastyear. This cost can be even lower forthose organizations that choose to com-bine their open systems SAN withtheir FICON connectivity and operatea FICON/FCP intermix environment.

• FICON processors (possible): Pre-9672S/390 G5 mainframes aren’t FICON-capable.

• FICON controllers: If you have exist-ing ESCON DASD arrays or tapedrives and the leases haven’t yetexpired, you have at least four options.You can leave them as ESCON. Youcan implement FICON bridge cards(FCV) into the model 5 ESCON direc-tors, and run your FICON at 1Gbps.You can upgrade controllers toFICON. Or, you can implement proto-col converter technology that convertsnative FICON to ESCON for attach-ment of legacy devices to FICON main-frame channels. This technology willlet you migrate your mainframes toFICON, run native FICON channelsinto the converter (via a FICON direc-tor, if desired), and run ESCON chan-nels out of the converter to yourexisting ESCON storage.

Now, let’s explore some specifics,starting with the DASD environment.

Justifying FICON in Your DASD EnvironmentFICON has been available for more

than three years, yet it has not beenwidely implemented. Those organiza-tions that have implemented FICONdid so primarily because they had a realneed to overcome the device addressand performance limitations associatedwith ESCON. To fully realize the bene-fits of FICON, you must have CPU,DASD, and directors that all supportFICON. Often, this can mean wholesalereplacement of the existing environ-ment, an expensive proposition. Further,most IT departments don’t view theirexisting ESCON performance as a limit-ing issue, so the case for investing inFICON was difficult—until now. Thejustification process doesn’t need toresult in an all-or-nothing proposition. Itcan be cost-effective to do “rollingupgrades” of your FICON storage andimplement new technology that allowsconverting native FICON on the host tonative ESCON for your ESCON storagethat may have lease life remaining.When the lease life is over, you thenmigrate those legacy ESCON DASDarrays to new FICON arrays.

The industry is coming to a point

where older, ESCON-capable equip-ment is being phased out of the supportand maintenance matrix, making thatequipment expensive to maintain. Oneway to reduce ongoing costs is to replaceolder equipment with new, FICON-capable equipment that comes with awarranty. Once this occurs, the move toFICON is inevitable; the hardware is inplace and it simply requires some config-uration changes. Figure 1 compares thetechnical specifications and features ofFICON to ESCON.

FICON can transfer data faster, far-ther, to more volumes per link, withfewer links than ESCON. Today’s main-frame environment strains the limits ofESCON. FICON provides relief fromthese limitations. FICON lets organiza-tions use more storage per DASD subsys-tem without changing to larger volumesizes and with the same or betterresponse times. This translates intorequiring fewer subsystems and chan-nels to support a given mainframeDASD environment. In other words,migrating your DASD environmentfrom ESCON to FICON is not justabout channel consolidation; it’s aboutfewer serial numbers!

The ESCON limitations of 1,024addresses in a DASD environment run-ning mod 3 disks translates, on average,into requiring a new DASDarray/frame/footprint every 3 to 4TB.These same ESCON DASD frames hadan average advertised capacity of 7 to11TB. You couldn’t fully use the frameyou purchased due to ESCON limita-tions. Today’s FICON-capable DASDarrays have an average advertised capaci-ty of 20 to 80TB. Much more of thatarray can be used in a mainframe envi-ronment due to FICON’s relief of theESCON limitations. Fewer serial num-bers translates into real cost savings spe-cific to hardware, floor space,power/cooling, management, and soft-ware such as advanced copy features.

FICON in Tape Environments When discussing FICON, DASD

comes to mind first, but FICON can pro-vide benefits in the tape environment,too. It lets today’s tape drives run at theirrated speeds. Virtual tape systems canbenefit from FICON, letting themaccept and deliver more tape workloadfrom the host while using fewer chan-nels. With tape and virtual tape, too, it’snot just about channel consolidation; it’sabout fewer serial numbers.

The IBM 3592 operates at 35MB/secuncompressed. ESCON cannot feed the

The hardware

costs aren’t the

most significant

cost variable in

a mainframe

environment;

software and

maintenance

costs dominate

the budget.

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drive to let you get your money’s worth.Meanwhile, you can put two to three ofthese 3592 drives onto a FICON channel,while you could have only one tape driveper ESCON channel. The IBM 3592 tapedrive provides three times the speed andfive times the capacity of the IBM 3590Htape drive. These increases will reducethe time needed to move data to tape andwill let you use fewer tape cartridges andreduce the number of 3494 slotsrequired.

Let’s say we studied the tape environ-ment for the hypothetical ABCCompany. Based on the estimated3590H requirements for ABC Company(55 drives for all the workload, 40 drivesfor 97 percent), the following showshow this would directly translate into3592 tape drives:

• 55 3590H = 18 3592 drives• 40 3590H = 14 3592 drives.

For virtual tape, with a given controlunit at the front-end, using FICONrather than ESCON reduces the num-ber of control units, back-end tapedrives, and channel paths required.Virtual tape systems are typically sizedpartly on front-end connection through-put. FICON has a front-end throughputthat is approximately 80 to 100 percentmore than ESCON. The exact numbersdepend on the vendor and virtual tapesubsystem model. So, with ESCON, youmay be required to purchase additionalvirtual tape subsystems much earlierthan you would with FICON. Again,FICON leads to fewer serial numbersthan ESCON, which translates into realsavings. A point of caution is in orderhere: We don’t recommend followingsimple rules of thumb cited by much ofthe vendor marketing literature. Onecommon rule of thumb is for consolida-tion ratios (4:1, 8:1, etc.). It is importantto understand the workloads, and thatdifferent workloads will require differ-ent consolidation ratios. We recom-mend analyzing RMF and SMF recordsand using performance modeling toolsto model a FICON environment andwhat the response times are for a givenconsolidation.

The Connectivity InfrastructureBeginning next year, IBM will no

longer sell the 9032-5 ESCON director.Existing ESCON customers who desireto maintain or grow their ESCON envi-ronments will need to purchase ESCONdirectors from other sources. Much ofthe ESCON director infrastructure in

place today is owned by users. However,monthly maintenance on ESCON direc-tors can be quite high (as much as$20,000 annually).

If you have a large ESCON environ-ment, maintenance costs add up fast.Often, the purchase price of FICONdirectors can be partially or fully justi-fied by eliminating ESCON directorsand their associated maintenance costs.ESCON directors are also much largerthan the new FICON directors availabletoday. A FICON director can have 512FICON ports in a single floor-tile-sizerack. That is the equivalent of 1024-4096ESCON ports in that floor tile space.The same floor tile can hold one 9032-5ESCON director (248 ports fully popu-lated). ESCON directors are also muchmore expensive to operate in terms ofpower and cooling requirements.

Unlike FICON, ESCON Channel-to-Channel (CTC) protocol requires a ded-icated channel. A FICON channel can beused for both CTC and normal traffic.The cost savings associated can be signif-icant for large CTC mainframe shops.

Finally, FICON lets you leverage asingle storage network for open systemsand mainframe storage, which is com-monly referred to as FICON-FCP inter-mix. In short, a common infrastructurecan be shared by open systems and main-frame storage will cost less to implementand manage.

Cost Savings on the HostThe hardware costs aren’t the most

significant cost variable in a mainframeenvironment; software and mainte-nance costs dominate the budget. Bothsoftware and maintenance costs arebased on MIPS. FICON, by allowingI/O to complete faster, reduces theprocessor cycles required for a givenjob. We hypothesize that FICON couldlet you run fewer MIPS in your envi-ronment than you would with ESCONto complete jobs in the same amount oftime. For example, many customerslooking at migrating to FICON aredoing so as part of a mainframeupgrade project. What ran on an eight-engine ESCON older mainframe maybe able to run in the same time on aseven-engine FICON mainframe. Thiswould represent the largest cost savingsin your environment. We are planningto test this theory in the lab.

New Technology Facilitates MigrationThere’s a new technology projected

for release at the end of the year that willlet ESCON storage devices attach directly

to native FICON channels from the main-frame. Many organizations that haven’tyet begun a migration to FICON haveheld off primarily for financial reasons.These relate to their large investment inESCON DASD frames or tape and virtu-al tape subsystems that are still on lease orthat haven’t fully depreciated. Moving toFICON may make technical sense, butnot financial sense based on the invest-ment required for new FICON storagesooner than planned. The FICON bridgesolution doesn’t make technical sensecomparatively because it doesn’t offer thebenefits of native FICON connectivity.FICON Bridge (FCV) is half-duplex,restricted to eight simultaneous I/Os, anddoesn’t have the full addressing capabili-ties of native FICON. FCV cards are alsovery expensive, and using them meansyou must keep those ESCON directors onthe floor (and keep paying maintenanceon them). Doing a conversion of nativeFICON to ESCON using the new tech-nology doesn’t require an ESCON direc-

ESCON

channels

won’ t always

be available

on mainframes

(remember, the

z990 doesn’ t

offer parallel

channels), so

migration to

FICON is

inevitable.

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tor. It’s a better solution technically, andthe overall TCO is lower.

Moving ESCON storage to FICON ina phased manner would be much sim-pler on personnel and much easier tomanage. The host/mainframe could beupgraded to be predominantly FICON,while the ESCON storage is consolidat-ed/replaced by new FICON storage asleases come due. The remaining ESCONstorage devices can then be attached tothe FICON network, allowing elimina-tion or consolidation of ESCON chan-nels and ESCON director ports. TheESCON storage may eventually bereplaced by new FICON storage. TheFICON-ESCON converter can then beredeployed for attaching other devicessuch as printers or front-end processors.Or, if the ESCON storage is owned out-right, it can be kept and leveraged as tier-2 storage. This new conversiontechnology provides investment protec-tion and facilitates a phased FICONmigration approach that coincides withleasing cycles for storage. This type ofmigration tends to be much more practi-cal and convenient.

SummaryThis article offers ideas on how you

can justify migrating from ESCON toFICON. FICON has been available formore than four years and is a proven

technology, yet only about one-quarterof all ESCON shops have implementedFICON. This is due largely to theexpense associated with migration.However, we’ve shown ways that mov-ing to FICON can save your organizationreal dollars.

There are also new technologies inplace that let you phase these costs in byprotecting your investments in existingstorage devices and achieving their fulluseful life. ESCON channels won’talways be available on mainframes(remember, the z990 doesn’t offer paral-lel channels), so migration to FICON isinevitable. So, will you do it sooner andrealize the technical and financialreturns now, or do it later and delay youropportunity?

Additional Reference MaterialI B M R e d b o o k : F I C O N N a t i v eImplementation and Reference GuideFICON and FICON Express ChannelPerformance, Version 2, by Cathy Cronin“The IBM Enterprise SystemsConnection (ESCON) Architecture,”IBM Journal of Research and Development,Volume 36, #4 (1992) by J.C. Elliot andM.W. Sachs MVS I/O Subsystems: ConfigurationManagement and Performance Analysisby Gilbert Houtekamer and Dr. H. PatArtis Z

Sean Seitz is vicepresident of BusinessDevelopment at OpticaTechnologies Inc., aconnectivity andinfrastructure solutionscompany focused inthe enterprise datacenter arena. His ITexperience exceeds 17

years and includes business management positionsin consulting services with McDATA, FujitsuTechnology, and Amdahl Corp.e-Mail: sean.seitz@opticatech.comWebsite: www.opticatech.com

Steve Guendert is CNTTechnical SolutionsGroup’s Storageprincipal consultantand is the director oftheir FICON practice.He is a PMI certifiedProject ManagementProfessional (PMP),and has M.B.A. and

M.S. degrees in Management Information Systems.He is a well-regarded FICON consultant, and is oneof the industry’s experts on the subject. Helectures and consults regularly on FICON andbusiness case justifications for migrating fromESCON to FICON. e-Mail: stephen_guendert@cnt.comWebsite: www.cnt.com

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