FLEX-ES, ® the FLEXible Enterprise Solution from Fundamental Software, Inc., provides innovative solutions to the problems of bringing the stability of mainframe operating systems and applications into the flexibility of new Intel®-based technology.
FLEX-ES is a System/390TM mainframe computer implemented in software.
This document provides a general technical introduction to FLEX-ES, highlighting its concepts, features, and capabilities.
Additionally, FLEX-ES emulated peripherals and certain physical server devices may be attached to traditional mainframes from other manufacturers using both ESCON® and parallel channels. This capability is also available separately as the FLEXCUB product (FLEX Control Unit Behavior), together with additional optional capabilities for virtual tape management and remote DASD synchronization. For further information about FLEXCUB, please consult the FSI White Paper about FLEXCUB.
In 1964, IBM pioneered the separation of a computer's architecture from its implementation with the introduction of System/360. By defining the machine's logical architecture as independent of the technology of its implementation, IBM enabled the same machine to be implemented using a variety of different technologies. Since then, this architecture has evolved from System/360 through System/370,TM 370-XA, ESA/370, ESA/390 (System/390®), to today's 64-bit z/Architecture.TM This well-proven family of computer architectures remains a significant force in the business world in part because its implementations have always kept pace with the latest technologies. FLEX-ES from Fundamental Software, Inc., employs one of the latest of these technologies: software implementation.1
The FLEX-ES software mainframe runs as an application program on modern Intel® Pentium® processor series servers running, as a host environment, the UnixWare® or Linux® operating systems. It provides full-featured uniprocessor and multiprocessor 31-bit mainframe CPU complexes, along with a wide range of emulated devices and the capability to attach to physical peripherals.
A 31-bit mainframe operating system such as z/OS,® z/VSE,® z/VM,® or Linux®/390 runs "on top" of FLEX-ES. Mainframe applications in turn run on top of the mainframe operating system. Because FLEX-ES is an implementation of the machine architecture itself, these mainframe operating systems and applications run with no modification. From the point of view of the mainframe software, FLEX-ES is logically indistinguishable from a traditional hardware mainframe.
FLEX-ES may be supplied with peripheral devices in several ways.
It supports the channel attachment of both ESCON (serial) and older OEMI (parallel, "bus and tag") physical peripheral devices through several optional FSI channel cards.
It provides emulated devices of many types. These devices use the resources of the host server to provide functionality equivalent to traditional peripherals.
It allows the use of SCSI attached server tape drives as mainframe devices (these include mainframe compatible SCSI tape drives such as 3420 series compatible drives and 3480 series compatible drives as well as server cartridge drives such as DLT drives).
It provides an optional Integrated Communications Adapter (FSI ICA) card.
Beginning with Release 7, FLEX-ES emulated devices may be channel attached to traditional hardware mainframes from other manufacturers using the optional FSI SCA-1 (serial, ESCON) and FSI PCA-1 (parallel, OEMI) channel cards. This capability is also available separately as the FLEXCUB product (FLEX Control Unit Behavior), together with additional optional capabilities for tape management and remote DASD synchronization. For further information about FLEXCUB, please consult the FSI White Paper about FLEXCUB.
A FLEX-ES installation on a server consists of a number of components, some required and some optional. These include:
Each FLEX-ES emulated CPU complex (called an "Instance" in FSI terminology) runs as a server application program on the host server. The host server runs the UnixWare or the Linux operating system to provide a host environment for FLEX-ES. Each Instance provides a uniprocessor or multiprocessor mainframe CPU complex which is logically independent of any other Instances on the server. Upon each Instance, therefore, a separate mainframe operating system runs, and on it, in turn, mainframe applications run (or other mainframe operating systems, if VM is running on top of the Instance).
(Note that the host operating system running on the server (UnixWare or Linux) is entirely independent of the mainframe operating system running on top of FLEX-ES. It is quite possible to run an Intel Linux as the host OS on the server and a System/390 Linux as the mainframe OS on top of FLEX-ES.)
A FLEX-ES Instance is provided entirely through software (using the server's hardware capacity, of course). FLEX-ES is a software mainframe which is not based on microprocessors or other hardware components. The FSI channel cards used with FLEX-ES are optional components used when specific mainframe hardware interfaces not present on the server are required.
Because an Instance is simply a server application program, other Instances and other server applications may run on the server at the same time as an Instance.
Only a very few small components of FLEX-ES need to be compiled into the server operating system kernel. These are all invisible to the user and do not affect the running of other server applications.
The many emulated mainframe peripherals FLEX-ES provides are, similarly, implemented as application level software on the server.
Most emulated devices rely ultimately upon the hardware resources of the server. Emulated DASD, for example, require space on server RAID, emulated Ethernet (3172/XCA/OSA/etc.) requires server Ethernet (or server "TUN" virtual Ethernet), emulated Token Ring requires server Token Ring, emulated 3270 terminals use the server's networking capabilities (TN3270E), emulated tape requires server disk space, and so forth. These requirements for server resources aside, all emulated devices are implemented in software.
One variation on this is that of the devices providing BSC and SDLC as plug-compatible replacements for some of the functionality of certain mainframe Integrated Communications Adapters (ICAs). While these BSC and SDLC devices are emulated in software, they rely not on conventional server hardware, but upon hardware resources provided by the FSI Integrated Communications Adapter (FSI ICA). These BSC and SDLC integrated peripherals and the FSI ICA are optional components of FLEX-ES.
Certain server attached SCSI tape drives may be used as mainframe peripherals with FLEX-ES. These tape drives include both mainframe compatible tape drives ("round" tape of 3420 and related drives and "square" tape of 3480 and related drives) and server cartridge tape drives (DLT and DAT(DDS)). Regardless of the drive technologies, these SCSI tapes appear to a FLEX-ES Instance as mainframe tape drives.
Note: Tape devices of type 3590 are supported as emulated tape drives and physical 3590 peripherals via the FSI SCA, but there is no SCSI support for "3590" devices.
To provide connectivity to physical mainframe peripheral devices, FLEX-ES provides two optional components: the FSI Serial Channel Adapter (FSI SCA) for the connection of ESCON and ESCON-compatible peripherals (including ESCON Directors) and the FSI Parallel Channel Adapter (FSI PCA) for the connection of OEMI (bus and tag) peripherals.
The CPU and device "resources" provided by FLEX-ES are managed on each server by a Resource Manager. The FLEX-ES resource manager provides a uniform view of all resources. The FLEX-ES resources of a server, under the control of the Resource Manager, are best thought of as a complete virtual machine room floor.
Each FLEX-ES Instance may be controlled interactively through its emulated main console. This emulated main console is, however, not accessed directly but instead is accessed through zero or more "Command Line Interface" (CLI) sessions. These CLI sessions run over the network. A CLI application running on the local FLEX-ES server or on remote FLEX-ES servers provides an interactive console as well as the ability to automate and script actions. (To run a CLI session from a computer which is not a FLEX-ES server, simply connect to a FLEX-ES server using any conventional terminal communications program and run the CLI console on the server.)
Together with emulated mainframe telecommunications features such as 3270 terminal sessions over the server network, this enables remote diagnostics and support of FLEX-ES emulated mainframes and their mainframe operating systems and applications.
Each FLEX-ES server maintains a single "Terminal Solicitor" which manages inbound emulated 3270 terminal sessions. The Terminal Solicitor presents to the user a choice of available 3270 terminals to which to connect. (It is also possible to configure a 3270 terminal line to bypass this interactive step and to connect directly.)
FLEX-ES is a true Plug-Compatible Mainframe (PCM) which may be configured as a drop-in replacement for many existing mainframe installations. However, FLEX-ES goes beyond conventional plug compatibility. This product provides a level of configurability and a diversity of device support which make it the Flexible Enterprise Solution. The capabilities FLEX-ES provides include:
At the present time, FLEX-ES does not include support for certain capabilities, including the following:
(Note: While FLEX-ES does not provide PR/SM, it does provide certain functionality which is addressed by PR/SM in IBM mainframes, including the ability to run multiple independent emulated CPU complexes on the same server.)
When run on a multiprocessor host server, FLEX-ES can provide a multiprocessor (MP) emulated mainframe CPU complex up to the limits defined by the System/390 architecture. Because the emulated mainframe is a processor-intensive application, there is a required one-to-one correspondence between CPUs in an emulated CPU complex and server processors. To enhance performance, it is possible to configure an emulated CPU complex (an "Instance") to bind individual mainframe processors to individual Intel processors on the host server so that they have the exclusive use of that host processor.
In addition to the mainframe capabilities of FLEX-ES, because FLEX-ES runs as a user-level application program on the host server, all of the resources on the host server are available simultaneously with the FLEX-ES mainframe. UNIX/Linux and mainframe applications can coexist on the same server. Communication between mainframe applications and UNIX/Linux applications is possible using a variety of methods, including TCP/IP networking, emulated tape, and emulated card equipment. The FakeTapeTM Programming Library, supplied with FLEX-ES, allows UNIX or Linux application to be be developed which can create, read, and write emulated mainframe tapes.
Multiple "Instances" of FLEX-ES may run simultaneously on the same server2, just as multiple instances of any UNIX/Linux application program can run on a single server. Each Instance of FLEX-ES is, logically, a completely separate mainframe computer. A separate mainframe operating system runs on top of each Instance. (Note that multiple simultaneous Instances may require multiple mainframe operating system and application licenses, as required by the customer's licensing agreements with IBM and other vendors.)
This capability is different from the Logical Partitions (LPARs) provided by IBM's PR/SM. FLEX-ES does not implement PR/SM or provide LPARs. However, the ability to run multiple Instances simultaneously (and thus multiple mainframe OSs) addresses many of the same needs addressed by LPARs.
This capability is also different from the capabilities provided by VM, although in practice it may be used to the same end. VM, IBM's "Virtual Machine" operating system, takes the resources of a mainframe CPU complex and "virtualizes" them so that they appear to be several machines. One instance of VM, running on a machine of a particular architecture, provides multiple virtual copies of that same machine architecture. In contrast, FLEX-ES provides a machine of one architecture (System/390, etc.) on top of a machine of a different architecture (an IA-32 server). Running multiple instances of FLEX-ES provides multiple separate mainframes which happen to reside on the same physical server. FLEX-ES does not "virtualize" the mainframe in the same way that VM does. Nevertheless, FLEX-ES can provide multiple mainframes on the same server, each running its own mainframe operating system. When the primary purpose of VM is to provide multiple mainframes, multiple instances of FLEX-ES can provide equivalent functionality through different means. VM does, however, provide a finer degree of control of the allocation of resources between mainframes, and may be used to advantage in conjunction with FLEX-ES.
For further information about FLEXCUB, please consult the FSI White Paper about FLEXCUB.
FLEX-ES supports IBM's System/390® architecture in 31-bit mode.
Separate operating modes are provided for support of legacy and other systems which must operate in ESA/390 ("System/390"; including ESA/370 and 370-XA), System/370, or ECPS:VSE modes.
FLEX-ES supports most older IBM operating systems in 31-bit mode, as appropriate for the operating system release. Supported OSs include:
|VSE||All releases of the VSE family of operating systems, from DOS through DOS/VSE to z/VSE® 3.1 in 31-bit mode.|
|OS||All releases of the OS family of operating systems, from OS/360, through MVS and OS/390,® to z/OSTM 1.5 in 31-bit mode.|
|VM||All releases of the VM operating system to z/VMTM 4.4 in 31-bit mode.|
|Linux/390||IBM's port of the Linux® kernel to System/390.|
In addition, FLEX-ES supports mainframe operating systems from other vendors, including:
|UTS||All releases of the Amdahl® UTS® mainframe UNIX® operating system.|
FLEX-ES supports all system services and applications which run under these mainframe operating systems, except those which require specific features or facilities not implemented by FLEX-ES (such as hardware cryptographic facilities, for example).
It is important to remember that FLEX-ES supports operating system and application software by providing a mainframe computer on which these systems and applications run. FLEX-ES itself does not implement any part of these mainframe programs. They run without modification on the FLEX-ES mainframe system itself.
It is the customer's responsibility to obtain all IBM and third party operating system and application licenses at the appropriate performance or other rating for the FLEX-ES system(s) they have installed.
FLEX-ES supports a comprehensive range of physical and emulated peripheral devices of many types:
There is some overlap between the support provided by these methods. For example, 9-track tape is supported by emulated devices (FakeTapeTM and AWSTAPE), SCSI attached 9-track tape drives, SCSI attached cartridge tape drives (DAT, DLT), and channel attached mainframe peripherals (real 3420s, for example).
FLEX-ES provides many emulated devices, including emulated tape drives, printers, card equipment, Ethernet and Token Ring communications controllers for TCP/IP and SNA, 3270 terminals over TCP/IP, and virtually all CKD, ECKD, and FBA DASD. These emulated devices are implemented in software. When necessary, they take advantage of hardware and system services provided by the host server and its network. For example, emulated DASD use the disk resources of the host server, and emulated terminals use the network services provided by the host.
Emulated devices may provide significant economic and operational advantages over physical peripherals. Because they are built out of software, they can be created and reconfigured as necessary to build or match any configuration3. Emulated 3270 terminal networks may take advantage of new or existing TCP/IP intranets to replace dedicated 3270 networks. Emulated CKD, ECKD, and FBA DASD using disks on the server are faster and less expensive than traditional mainframe DASD.
(Note: Certain other devices have emulated aspects. For example, the devices provided by the FSI ICA are emulated devices which take advantage of the FSI ICA and server hardware, and the configuration of SCSI attached server tape is closely integrated into emulated tape drive support. Because of their special characteristics, however, FSI ICA and SCSI attached devices will be treated in separate sections here.)
FLEX-ES supports virtually all mainframe CKD, ECKD, and FBA DASD as emulated devices:
CKD and ECKD DASD:
In addition, (E)CKD and FBA DASD of nonstandard sizes may be defined, including "3390-9" DASD of up to 32,760 cylinders.
Emulated DASD are implemented in software on a host server and employ the physical disks attached to the server. In a typical installation, these disks might be provided in a RAID array. FLEX-ES is not tied to any particular server disk technology.
Emulated DASD are both fast and very economical by comparison to traditional physical DASD. All emulated DASD, whatever the model being emulated, operate as fast as possible given the installation. Thus, an emulated 2305 and an emulated 3390 both operate at the same speed. Typically, these speeds greatly exceed the speeds of traditional physical mainframe DASD. All emulated DASD implement a cache. For CKD emulated DASD, this cache may be specified in the configuration as either write-back or write-through.
Emulated DASD implement all of the blocks, tracks, or cylinders of the equivalent physical DASD, including those not generally visible to users, such as alternate, Customer Engineering (CE), and Selective Availability (SA) blocks, tracks, or cylinders.
Emulated DASD support shared disk access. This allows any emulated DASD to be connected to up to 32 FLEX-ES emulated channel paths (with a maximum of one channel path per channel subsystem per DASD).
FLEX-ES looks at emulated DASD from the logical point of view rather than a physical one. For example, a physical 3380-A DASD contained two Head/Disk Assemblies (HDAs), each of which contained two access mechanisms. However, from a logical point of view each of these access mechanisms was accessible as a distinct device. Therefore, a FLEX-ES "3380A" emulated DASD corresponds in size to a single access mechanism on a physical 3380-A, because this is the logically addressable unit.
Fundamental Software defines a "Megabyte" as 1,024 kilobytes, or 1,048,576 bytes. Other manufacturers, including IBM, sometimes define a Megabyte as one million bytes. This, combined with the fact that the size of a FLEX-ES emulated DASD is calculated to include all alternate, CE, and SA blocks, tracks, and cylinders, and the fact that certain roundings occur during FLEX-ES emulated DASD size calculation, may cause the calculated size of a FLEX-ES emulated DASD to appear to be different than the size of the equivalent physical DASD.
Individual CKD emulated DASD may also be split over up to five server physical or logical disks. While this capability is less important with today's large RAID subsystems, in certain situations it can be advantageous.
FLEX-ES emulated tape drives support three emulated tape formats: FSI's "FakeTape," IBM's "AWSTAPE," and IBM's "OMA/2" format.
188.8.131.52 - FakeTape
FakeTape is FSI's own emulated tape format. FakeTape emulated tapes are written to server disk.
On the server side, the FakeTape format is documented, an Applications Programming Interface (API) to it is defined, and a FakeTape Programming Library implementing this API is provided. In addition, several examples of the server-side use of FakeTape are provided, together with a number of server commands to manipulate FakeTape files. It is possible, therefore. to build applications on the server which can read, write, and create FakeTapes. The server-side FakeTape utility programs may be incorporated into server shell scripts. These capabilities makes FakeTape a powerful medium for data exchange between server-side and mainframe-side applications.
On the mainframe side, FakeTape emulated tape drives are logically indistinguishable from physical tape drives. They appear just as if they were 3420 series or 3480 series tape drives.
FakeTapes may be mounted and unmounted by an operator using FLEX-ES Command Line Interface (CLI) commands. Once unmounted, a FakeTape "tape" may be handled like any other file on the server; it may be copied, moved, written to another medium, or exchanged with another system.
The FakeTape format is itself independent of the emulated drive type. FakeTapes written from any FakeTape emulated tape "drive" may be read on any other FakeTape drive - they are completely interchangeable with each other. For example, a FakeTape written from an emulated 3420 drive may be read on an emulated 3490-E drive.
184.108.40.206 - AWSTAPE
"AWSTAPE" was the name of the driver for the emulated tape support on the IBM P/390 and related server-based hardware (microprocessor) mainframes.
FLEX-ES emulated tape drives can read and write AWSTAPE format emulated tapes. In use, the AWSTAPE format is detected automatically. The drive is specified to the mainframe as a mainframe tape drive without further qualification (e.g., as a "3480"), and FLEX-ES responds appropriately when an AWSTAPE format emulated tape is mounted on it.
A standalone program is provided to create a blank AWSTAPE format tape so that new AWSTAPE format tapes can be created, written, and read.
220.127.116.11 - OMA/2
"OMA/2" was the IBM Optical Media Attach Type 2 device. It was an optical device, not a tape device, and was available in read-only models. It employed an underlying format that was a composite of tape formats. It is sometimes referred to as the "TDF" format after the Tape Descriptor File which organizes its "tapes."
FLEX-ES emulated tape drives can read OMA/2 format emulated "tapes" from server disk. No write support is provided (there never was an OMA/2 device available to customers which could write OMA/2 "tapes"). In use, the OMA/2 format is detected automatically. The drive is specified to the mainframe as a mainframe tape drive without further qualification (e.g., as a "3480"), and FLEX-ES responds appropriately when an OMA/2 format emulated tape is mounted on it.
18.104.22.168 - Supported Tape Device Types
The following tape device types are supported as both emulated tape devices (in FakeTape, AWSTAPE, or OMA/2) and as SCSI attached devices.
Tape devices of type 3590 are supported as emulated tape drives and physical 3590 peripherals via the FSI SCA, but there is no SCSI support for "3590" devices.
22.214.171.124 - 3270 Terminals Over TCP/IP
FLEX-ES provides support for emulated 3270 class terminals over server TCP/IP networks by supporting the TN3270 and TN3270E protocols. The 3270 class terminals so provided appear to the mainframe to be terminals attached to a local, channel attached, non-SNA 3274-41D or 3174 controller. The following terminal types are supported:
TN3270 is a protocol in the TCP/IP suite of protocols which allows the transmission of 3270 data streams over TCP/IP networks (such as TCP/IP corporate intranets or the Internet). The actual terminal emulation is provided by a "front end" 3270 terminal emulation program running on the user's machine in the TCP/IP network. FLEX-ES provides a 3270 terminal emulation program suitable for use with supported UNIX/Linux systems. Other compatible 3270 terminal emulation programs running in other environments (e.g., Windows®) may also be used.
Users connecting to a FLEX-ES server from the 3270 terminal program on their local or remote machine connect to the FLEX-ES "Terminal Solicitor," an interactive program which displays the available terminal lines and allows them to establish their terminal session. It is also possible to configure terminal lines such that they detect the IP address from which the user is connecting and automatically establish the session, bypassing the interactive use of the Terminal Solicitor.
The use of emulated terminals over TCP/IP networks may be advantageous because it allows easy configuration, reconfiguration, and expansion of terminal networks using TCP/IP networks. As TCP/IP inter- and intra-networks are increasingly common, this option allows hardwired 3270 terminal networks to be phased out in favor of virtual 3270 networks built on top of a modern network infrastructure.
126.96.36.199 - 3172 Ethernet and Token Ring
FLEX-ES provides emulated control units and devices with functionality equivalent to the Ethernet® and Token Ring capabilities of an IBM 3172 Communications Controller. These emulated devices use the networking hardware of the host server (certain restrictions may apply in specific server environments).
188.8.131.52 - XCA and OSA Ethernet and Token Ring
FLEX-ES provides emulated control units and devices with functionality equivalent to a subset of the IBM OSA (Open System Adapter) functionality, including Token Ring, 10 Base-T Ethernet, and 100 Base-T Ethernet. Other OSA functionality, such as FDDI and ATM networking, is not supported.
FLEX-ES also provides emulated control units and devices with functionality equivalent to a subset of IBM XCA functionality (IBM External Communications Adapter; VTAM major node "TYPE=XCA").
These emulated devices use the networking hardware of the host server (certain restrictions may apply in specific server environments). In the Linux host server environment, the "TUN" virtual Ethernet device may also be used instead of physical Ethernet hardware.
184.108.40.206 - CETI Ethernet and Token Ring
FLEX-ES provides emulated control units and devices with functionality equivalent to the CETI (Continuously Executing Transfer Interface) Ethernet and Token Ring (4 and 16 Megabit/second) control units integrated into certain traditional IBM mainframes. These emulated devices use the networking hardware of the host server (certain restrictions may apply in specific server environments).
Certain mainframe operating systems provide support for TCP/IP over CETI Ethernet and Token Ring. Certain mainframe operating systems provide support for SNA over CETI Token Ring.
220.127.116.11 - k200 Ethernet
FLEX-ES provides an emulated communications controller and device with functionality equivalent to a Spartacus Inc. / Fibronics Inc. K200 mainframe Ethernet controller. This emulated device uses the networking hardware of the host server (certain restrictions may apply in specific server environments).
Certain mainframe operating systems provide support for TCP/IP over K200 Ethernet.
18.104.22.168 - TWX (ASCII) Terminals
FLEX-ES provides emulated TWX ASCII terminals. It implements as an emulated device the ASCII Telegraph Adapter Type II Transmission Adapter Feature of the IBM 2701 Data Adapter Unit for use with Common-Carrier Teletypewriter Exchange ("TWX") Model 33 and Model 35 terminal equipment. This emulated device is provided in both TTY-style and X Window System environments.
FLEX-ES also supports server serial and modem attached ASCII terminals as TWX devices, and the FSI ICA provides ASCII communications functionality.
22.214.171.124 - 3215 Console
FLEX-ES provides an emulated 3215 console. This console appears as a window on the screen of the host server (or on another server using the distributed windowing capabilities of the host server's X Window System).
126.96.36.199 - BSC
FLEX-ES provides fully emulated BSC (BiSynchronous Communications) lines between FLEX-ES systems. (This capability is distinct from BSC provided over the FSI ICA.) The use of this capability should be discussed with your FSI authorized FLEX-ES Reseller. Corresponding fully emulated SDLC support between FLEX-ES systems (other than that provided over the FSI ICA) is not provided.
FLEX-ES also supports, of course, BSC and SDLC over the FSI ICA.
FLEX-ES provides the following printers as emulated devices:
These emulated devices may be configured to print to files on the server, to physical printers attached to the server, or to the server's printing system.
Physical mainframe printers are also supported as FSI SCA and FSI PCA attached peripherals.
FLEX-ES provides emulated 2501 card readers and emulated 2540 card reader/punches. These devices read and "punch" emulated card format files to the server.
Physical mainframe readers and punches are also supported as FSI PCA attached peripherals. Yes, we test this.
FLEX-ES provides an emulated Channel-to-Channel Adapter. This emulated device is useful for linking two FLEX-ES emulated mainframes.
While the emulated CTC cannot, of course, connect to a physical mainframe, FLEX-ES supports physical Channel-to-Channel Adapters such as the IBM 3088 using the FSI PCA. The FSI SCA provides only type CNC channels; it does not provide type CTC channels.
The FSI Serial Channel Adapter (FSI SCA) provides serial channel (ESCON compatible) peripheral connectivity. Multiple FSI SCA cards may be used, up to the PCI bus limits of the server. It is available in a single channel version, the FSI SCA-1. The FSI SCA-1 supports two distinct modes of operation: Channel Behavior, in which it provides a conventional ESCON compatible channel to one or more FLEX-ES emulated mainframes, and Control Unit Behavior (FLEXCUB), in which it attaches FLEX-ES emulated device control units and their devices to ESCON or ESCON compatible channels of mainframes from other manufacturers. The FSI SCA-1 may be configured for Channel Behavior or Control Unit Behavior, but not for both simultaneously. This section will discuss only Channel Behavior. For further information about FLEXCUB, please consult the FSI White Paper about FLEXCUB.
The FSI SCA-1 implements type CNC channels (but not type CTC, CVC, or CBY channels). All ESCON peripheral devices which may be connected to type CNC channels, and all ESCON directors, may be attached. ESCON is always a block multiplexing protocol in CNC mode. Because it provides only type CNC channels, neither ESCON-to-OEMI channel converters (requiring type CVC or type CBY channels) nor ESCON CTC (requiring type CTC channels) are supported.
Multiple Instances on the same server may share a single FSI SCA port. This addresses some of the same issues as IBM's ESCON Multiple Image Facility (EMIF).
The FSI Parallel Channel Adapter (FSI PCA) provides parallel channel ("OEMI," "Bus & Tag") peripheral connectivity. Multiple FSI PCA cards may be used, up to the PCI bus limits of the server. It is available in versions which provide either one channel (FSI PCA-1) or three channels (FSI PCA-3) per card. The FSI PCA-1 supports two distinct modes of operation: Channel Behavior, in which it provides a conventional OEMI parallel channel to a FLEX-ES emulated mainframe, and Control Unit Behavior, in which it attaches FLEX-ES emulated device control units and their devices to OEMI channels of mainframes from other manufacturers. (The FSI PCA-3 supports only Channel Behavior.) This section will discuss only Channel Behavior. For further information about FLEXCUB, please consult the FSI White Paper about FLEXCUB.
The FSI PCA supports most OEMI peripherals. It can operate in both DC Interlocked mode and in Data Streaming mode. In Data Streaming mode it supports transfer rates of up to 4.5 Megabytes/second. Each PCA card comes with a custom cable which adapts the card's connector appropriately to one or three pairs of bus and tag cable ends.
Supported devices include:
Some less common or third-party devices have not been tested. Please consult your FSI authorized FLEX-ES Reseller if you have unusual device requirements.
FLEX-ES supports certain FSI-certified SCSI attached physical 9-track tape drives as if they were 3420 style tape drives (3420 (-4, -6, -8), 3422, 3423, 3430). Tapes written with SCSI attached 9-track tape drives are physically compatible with traditional mainframe 9-track tapes (open reel round tapes).
FLEX-ES tape drives configured as 3420 style drives may handle both SCSI attached and emulated (FakeTape, AWSTAPE, OMA/2) tapes without reconfiguration. FSI SCA and FSI PCA attached physical tape peripherals are, however, configured separately.
The configuration of a drive of a particular speed (e.g., 3420-4 vs. 3420-8) affects the sense information returned. The actual speed of the drive is, of course, determined by the tape drive hardware itself.
FLEX-ES supports certain FSI-certified SCSI attached physical mainframe cartridge tape drives as if they were 3480 or later style tape drives (3480, 3490, and 3490-E). Tapes written with SCSI attached mainframe cartridge tape drives are physically compatible with corresponding traditional mainframe cartridge tapes.
FLEX-ES tape drives configured as 3480 or later style drives may handle both SCSI attached and emulated (FakeTape, AWSTAPE, OMA/2) tapes without reconfiguration. FSI SCA and FSI PCA attached physical tape peripherals are, however, configured separately.
Note: Tape devices of type 3590 are supported as emulated tape drives and physical 3590 peripherals via the FSI SCA, but there is no SCSI support for "3590" devices.
FLEX-ES also supports modern cartridge tape drives on its host server (e.g., DAT/DDS or DLT) as if they were any model tape drive supported by FLEX-ES (3420-x, 3422, 3423, 3430, 3480, 3490, 3490-E) except model 3590. Server cartridge tapes are economical, high-capacity, and easy to handle. The tapes for these drives are not, of course, physically interchangeable with conventional mainframe tapes, but in situations where such interchangeability is not required they can provide significant cost and space advantages.
Technical Note: Physical 9-track tape is an open-reel medium where tapes may be of arbitrary length. These tapes therefore have an end of tape mark to signal the advent of the end of the physical tape. Cartridge tapes such as DAT or DLT have no such mark. However, cartridge tapes are always of known length. It is therefore possible for the tape driver to assure that the end of the tape is never passed; these cartridge tapes have no need for an end of tape marker.
The FSI Integrated Communications Adapter (FSI ICA) is an optional card which provides six communications lines which may be configured as binary synchronous communication (BSC) lines, synchronous data link communications (SDLC) lines, or US ASCII Telegraph Control Type 2 (TTC2) lines in any combination. This allows the attachment, usually through modems, of remote equipment such as 3174 remote terminal controllers and 2780/3780 class BSC attached terminals.
The FSI ICA can support up to 6 BSC lines at up to 19.2 kpbs, and, depending upon application conditions, up to 3 or 4 SDLC lines at 56 kpbs.
The use of the FLEX-ES Integrated Communications Adapter (ICA) or of peripheral controllers attached via the FLEX-ES Parallel Channel Adapter (PCA) may be advantageous because it allows a FLEX-ES system to take advantage of existing terminal networks. This can eliminate conversion time, conversion cost, and the retraining of users.
Great variety exists in the devices attachable to BSC, SDLC, and TTC2 lines. Please contact your FSI authorized FLEX-ES Reseller to discuss your situation.
In addition to emulated TWX terminals as described above, physical ASCII terminals may be attached using serial ports or modems on the host server.
FLEX-ES runs on the following host servers, if the specific server and server OS combination has been certified by FSI. Not all devices are available on all platforms, and certain other limitations may apply to specific platforms.
Please contact your FSI authorized FLEX-ES Reseller to determine an installation appropriate for your needs.
FLEX-ES runs in production and development environments on FSI certified Intel® Pentium® processor family (IA-32) based uniprocessor and multiprocessor servers running FSI certified releases of the UnixWare® operating system.
FLEX-ES runs in development, not production, environments on FSI certified Intel® Pentium® processor family (IA-32) based uniprocessor laptop computers running FSI certified releases of the Redhat® Linux® operating system.
Because the FLEX-ES host servers run in office environments, FLEX-ES itself does not require a traditional mainframe machine room (raised floor, special power, special cooling, noise isolation). The low power consumption of the FLEX-ES host servers and disk arrays allows the use of small, economical Uninterruptible Power Supplies (UPSs).
Customers who wish to retain or obtain traditional mainframe peripherals (mainframe tape drives, printers, etc.) may find that these peripherals require a machine room environment.
FLEX-ES is sold through FSI authorized Resellers. For further information, please contact FSI.
The physical and software installation of FLEX-ES normally will be handled by your FSI authorized FLEX-ES Reseller.
As noted earlier, FLEX-ES may run in either an office environment or a machine room environment, depending upon the requirements of any mainframe peripherals used.
When using the optional FSI Serial Channel Adapter (FSI SCA) and Parallel Channel Adapter (FSI PCA) cards, appropriate cabling from the adapter card is supplied. Further conventional peripheral cabling will normally be necessary. The cabling characteristics and restrictions on the FSI SCA and FSI PCA are identical to those of traditional mainframe channels; no special restrictions apply. Depending upon machine room configurations, it may also be necessary to re-route cables to peripherals. When replacing existing mainframe peripherals, such as DASD, with FLEX-ES emulated devices, considerable savings of floorspace may be realized.
If the server is to be connected to the Internet or to any other non-secure network, then an appropriate corporate network security policy, including the provision of a secure firewall, must be in place before any such connection is made.
FLEX-ES is a Plug-Compatible Mainframe. The installation of mainframe operating systems and applications from their distribution media is the same as it would be with any mainframe installation.
Because a FLEX-ES system may be configured to match most existing system configurations, it is also possible to transfer an existing mainframe software installation from a system which is being retired to a replacement FLEX-ES system of the same Group or other rating.
NOTE: It is expected in such a situation that the old system is to be retired. All license terms for all operating systems and applications must be adhered to strictly.
The general procedure for such a replacement is first to quiesce the existing system and then to use standalone utilities to take a dump of it to tape. The FLEX-ES system is then configured identically, often using some of the existing system's peripherals. Then standalone utilities are used to restore the dump of the old system to the identically configured new system. When the FLEX-ES boots, the complete existing installation runs on it just as it had previously run on the old system. The old system is then decommissioned and the machine room floorspace it occupied is reclaimed.
With FSI SCA or FSI PCA cards, it is also possible simply to move existing channel attached DASD from the old mainframe to the new FLEX-ES mainframe.
From a technical point of view, FLEX-ES excels in four general areas:
FLEX-ES is a real System/390 mainframe with support for both ESCON and OEMI peripherals. It has no compatibility issues.
Flexibility may be the single greatest strength of FLEX-ES - that's why "FLEX" is in its name. It is available in single or multiprocessor configurations. It supports physical channel attached peripherals, emulated devices, SCSI attached devices, and an Integrated Communications Adapter. Its devices may be configured (and reconfigured) in software. Within the device limits specified in the FLEX-ES License Agreement, emulated devices may be instantiated at will. This may be especially valuable in testing and product evaluation environments, where systems must be configured to match diverse production environments.
As a single solution running unmodified mainframe operating systems and applications on open server platforms, FLEX-ES provides considerable opportunity for interoperability between these two environments. In particular, emulated 3172/XCA/OSA and the FLEX-ES FakeTape Programming Library and utilities provide opportunities for communication between the mainframe and the server.
As an emulated machine, FLEX-ES takes advantage of the best in new platform technologies. These include:
These commodity technologies are being driven by the marketplace and will continue to provide the best combination of performance and economy.
|1||It is also correct to speak of FLEX-ES as an "emulator," because it uses one type of technology (software) to provide services logically identical to those conventionally provided by another type of technology (hardware). An emulated mainframe CPU or peripheral is just another kind of mainframe CPU or peripheral. It is not correct to speak of FLEX-ES as a "simulator," because a simulator merely models a system without necessarily providing its functionality (a flight simulator, for example, doesn't actually fly).|
|2||Licensing restrictions may apply.|
|3||The maximum number of devices which may be configured on any FLEX-ES system may be limited by the FLEX-ES License Agreement. Emulated DASD require sufficient real storage on the host server's disks.|
The information in this document is subject to change without notice. This information is provided without warranty of any kind, either express or implied, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose, or non-infringement. If your jurisdiction does not allow the exclusion of implied warranties, then the above exclusion may be restricted in part. In no event will Fundamental Software, Inc., be liable for any damages, either direct or indirect, including but not limited to any lost profits, lost savings, or other incidental or consequential damages arising out of the use or inability to use this document or the information it contains, even if Fundamental Software, Inc., or an authorized representative of Fundamental Software, Inc., has been advised of the possibility of such damage, or for any claim by any other party. In addition, Fundamental Software, Inc., shall not be liable for any claim for damages arising out of the use or inability to use this information and based upon strict liability or Fundamental Software, Inc.'s negligence. If your jurisdiction does not allow the limitation or exclusion of liability for incidental or consequential damages, then the above limitation or exclusion may be restricted in part.
FLEX-ES is a registered trademark of Fundamental Software, Inc.
FLEXCUB is a trademark of Fundamental Software, Inc.
FakeTape is a trademark of Fundamental Software, Inc.
IBM, z/OS, z/VM, z/Architecture, System/390, Enterprise Systems Architecture/390, ESCON, and Enterprise Systems Connection Architecture are registered trademarks of IBM Corporation.
VSE/ESA, System/370, Enterprise Systems Architecture/370, System/360, and PR/SM are trademarks of IBM Corporation.
Linux is a registered trademark of Linus Torvalds.
UNIX is a registered trademark of The Open Group.
UnixWare and OpenUNIX are registered trademarks of The SCO Group.
Intel and Pentium are registered trademarks of Intel Corporation.
Ethernet is a trademark of Xerox Corporation.
Amdahl and UTS are registered trademarks of Amdahl.
Windows is a registered trademark of Microsoft Corporation.
All other trademarks or registered trademarks which may appear in this document are the properties of their owners and are used here for purposes of identification only.
Copyright © 1998-2012 by
Fundamental Software, Inc.
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