OpenVMS vs. Unix

1. VMS was first released 1977-10-25 for the 32-bit VAX-11/780 manufactured by Digital Equipment Corporation a.k.a. DEC (VAX-11 meant PDP-11 compatibility)
2. Rewritten in 1992 for the 64-bit Alpha AXP manufactured by Digital Equipment Corporation then renamed OpenVMS
3. DEC was purchased by Compaq in 1998.
4. As of 2001, Compaq still supports OpenVMS on both VAX and Alpha hardware platforms but no new VAX hardware was manufactured after 2000-09-30.
5. On 2001-06-25 Compaq announced they will port OpenVMS to Intel's Itanium (IA64) processor.
6. Compaq merged with HP on 2002-09-03 but will still be called HP
7. On 2003-01-31 OpenVMS engineering achieved "first boot" on Itanium (their definition of this phrase requires boot up, log in, enter a DCL directory command, receive the correct response without a crash)
8. OpenVMS: Timeline
9. On 2015-06-31 HP announced they were outsourcing OpenVMS to VSI (VMS Software Inc.) who committed to supporting OpenVMS on future Itaniums as well as a port to x86-64

1. First written using "PDP assembler" in 1969 by AT&T's Bell Labs for the 18-bit PDP-7 and 16-bit PDP-11 minicomputers (both manufactured by Digital Equipment Corporation)
2. Rewritten using "C" in 1972 ("C" originally was, and still is, a language built for portability. This is the main reason why Unix is usually the first OS ported to any new computer hardware architecture)
3. Only ran on DEC machines for the first 8 years of its existence (so contrary to popular myth, the DEC community didn't hate Unix; although DEC founder Ken Olsen did as well as VMS developer Dave Cutler)
4. Ported to Interdata 8/32 and IBM 360 in 1977
5. Ported to VAX in 1978 (mostly by Bill Joy)
6. TCP/IP added to VAX Unix in 1980
7. Since Unix was free to Universities, this OS was probably responsible for a large number of PDP + VAX sales.
8. Unix: Timeline

1. Name means Virtual Memory System
   Seems suspiciously similar to MVS (Multiple Virtual Storage) from IBM

1. Named because it was initially meant to be a single (uni = one) user version of the Multics operating system
2. It wouldn't be a single user OS for very long

1. Extensive understandable on-line help in English. Other languages include: Thai, Hanzi (Chinese), Hanyu (Chinese), Hangul (Korean)
2. Hebrew is supported in certain layered products like Motif and All-In-One.
   Note: there may be more languages I don't know about.

1. On-line help (in the form of "man" pages) are difficult to understand even if English is your first language and you're a techie

1. of high license fees by DEC (many industry professionals commented that DEC's choice of '$' for the standard DCL prompt was not an accident)
   
   • license fees improved when Compaq purchased DEC but OpenVMS marketing by Compaq was almost non-existent. However, Compaq did see fit to allow the start up of the OpenVMS hobbyist group as well as loosen up the OpenVMS Educational Program
   • marketing has improved since HP took over Compaq. In 2003, HP claimed the OpenVMS business was growing 10-12% per year.
2. initially DEC (Ken Olsen) refused to put TCP/IP on OpenVMS (this was first done by 3rd party vendors like SRI, TGV, Wollongong, and Process Software). DEC engineers had ported TCP/IP libraries from BSD into ULTRIX calling it UCX (Unix Communications eXtensions). After Compaq purchased DEC, UCX morphed into a product called "TCPIP Services for OpenVMS". Process Software now is the provider of two OpenVMS stacks, TCPware and MultiNet.

1. AT&T licensed it to universities for free (or almost free if you were outside the USA) which introduced a whole generation of future IT workers to it
2. Universities had access to the source code which was used to teach computer system design to engineering students
3. Universities, working with DARPA, developed TCP/IP networking for it which is the basis of today's Internet
4. Universities, like Berkeley, modified it and then re-licensed it to corporations for tiny fees because schools are for learning, not profit. Berkeley's main contributions were: "socket programming", "TCP/IP Networking", and "BSD" (Berkeley Standard Distribution)
5. In the case of free Unix today, companies make money by selling support agreements with Unix installations
6. During the breakup of the Bell System (1982-1984), AT&T tried to regain control of Unix then announced their intention to charge universities for access to the source code. This triggered a lot of forking which (ultimately) led to the marriage of GNU (everything rewritten except the kernel) and Linux (the kernel). The duo are now being continually improved by the brightest minds in the world.

1. EDT
   (command: $edit/edt)
2. EVE (Extensible VMS Editor) has no width limit
   (command: $edit/tpu)
3. TECO
   (command: $edit/teco)

1. ed
   (very primitive line editor at the same level as TECO which was first used by DEC on early PDP machines)
2. vi
   (a video screen version of 'ed')
3. vim
   (vi improved)
4. xedit
   available from x-windows, CDE, KDE (Linux), or Gnome
5. nano
6. pico

1. Can have multiple (up to 32k) versions of the same file name (which makes possible the easy introduction of new program executables without a reboot)
2. Directories are kept sorted (good for directory searches but adds overhead to file creation/deletion)
3. Built-in RMS (Record Management System) provides native support for stream (non-record), sequential, relative and indexed files. (Indexed files can contain up to 255 keys but you rarely encounter more than 4)
4. Advanced lock queuing via the "Distributed Lock Manager" (works across clusters) ensures every process gets access to shared resources without spin locking

1. Directories easily span storage devices (or host machines with NFS)
2. No built in support for relative or indexed files
3. No advanced lock management (access to shared resources is usually by spin locking)
4. MFS (memory file system) allows a fully functional file system to exist in memory. Very cool.
5. AdvFS (advanced file system) is only currently available on Tru64 but should appear on HP-UX by 2004 (oops, this port was cancelled)

1. DCL (Digital Control Language) which is a command line/batch interface with a name that is suspiciously similar to IBM's JCL (Job Control Language)

1. Bourne Shell
2. C Shell
3. Korn Shell
4. BASH (Bourne Again Shell) which is very popular on Linux systems

1. DCL's philosophy assumes the user is tired, hasn't had enough coffee, and is making mistakes. Every command is "syntax checked" and the whole line is bounced if a single error is detected. (this is humble and much more desirable, especially in a business environment where data losses cannot be tolerated)
2. command line options are prefixed with a forward slash ("/") like so
   $edit /tpu
3. A <space> is considered command punctuation while a <comma> is considered a list separator.

Examples:

1. Suppose you want to delete all files with an extension of "junk" but you accidentally enter (notice the space between the asterisk and the period)
   $ del * .junk;*

   This command will return a syntax error and immediately stop.

2. Suppose you want to delete all files with an extension of "junk" or "log", and you want interactive confirmation on every delete, and you want to log your actions
   $ del/confirm/log *.junk;*,*.log;*

   Note: a semi-colon is the version specifier so ";*" means all versions

3. Suppose you wish to delete all multiple versions of a file with the extension of ".log" but you wish to keep the 3 most recent versions
   $ purge/log/keep=3 *.log

   This command will allow you to execute the same command recursively into the current directory including subdirectories
   $ purge/log/keep=3 [...]*.log

1. Unix shells assume the user is not tired and intends everything that is typed. (this is very dangerous but is also very fast)
2. command line options are prefixed by one or two dashes.
   • Two dashes ("--"): always represents a single word-based switch
   • One dash ("-"): usually represents one or more single letter switches
     • the "-exec" switch associated with "find" is one of many exceptions
     • the "-march" switch associated with "gcc" is another
   Examples:
       this bad command "tar -help" sends four switches to tar
       is good command "tar --help" sends one switch to tar
3. A <space> is considered a list separator

Example:

1. Suppose you want to delete all files with an extension of "junk" but you accidentally enter the following command (notice the space between the asterisk and the period)
   # rm * .junk
   This command will first delete all files then (jumping to the next item in the list) will delete all files named ".junk". If you happened to insert a "-r" switch after the "rm" command, all the directories under your current position will be recursively deleted. If you were in the root directory, you could wipe your whole disk!

1. An extensive batch processing engine is built in (supported by DCL)
2. DCL scripts can be run interactively or submitted to a batch queue
3. By default, batch queues are visible to everyone on the system (great for system management)

1. Crude batch processing via the CRON interface
2. You need access to the CRONTAB of specific users in order to view/debug queuing parameters (bad for system management)
3. OpenVMS style batch processing support is available from 3rd party vendors (this is changing for Tru64)

1. Adding spooled devices (like printers) is almost child's play
2. By default, print queues are visible to everyone on the system (great for system management)

1. Adding spooled devices is very difficult without GUI tools

1. Variables (DCL symbols) can be declared as global or local. Global symbols allow a process to share data with their respective sub-processes
2. "logical names" come in four flavors: process, job, group, system, cluster. A system level logical name can be used like a system-wide variable to share information between unrelated programs and a reboot isn't required to make changes take effect

1. Exported variables allow shells to share information with their sub-shells
2. To the best of my knowledge, no "logical name" concept exists anywhere in the Unix world

1. System parameters are changed via the SYSGEN tool
2. The system gathers running statistics and saves them in a feedback file to be used by the sys$update:AUTOGEN tool

1. All OpenVMS processes (system and user) are forced to engage in quota-based resource management. A process may want to spawn forever or request use of the whole page-file but will not be allowed to do so.

1. While it is true that Unix didn't have quota-based resource management for quite some time, this feature began to appear in the mid to late 1990s

1. limited boot (via conversational boot)
   then dropping into SYSBOOT to set SYSGEN parameter STARTUP_P1 = "MIN"
   then typing CONTINUE
2. full boot:
   the starting system executes DCL script:
       sys$manager:SYSTARTUP_VMS.COM

0 = firmware
1 = single user
2 = multi-user (no networking)
3 = multi-user with networking
4 = see "man init" for info on your Unix
5 = multi-user with graphics
6 = see "man init" for info on your Unix
S = see "man init" for info on your Unix

For example, when the system is at level 1 the administrator enters "init 2" or "init 3" to open the system to other users.

1. sys$manager:SYSTARTUP_VMS.COM

1. sys$manager:SYSHUTDWN.COM

1. HP drops the price. Remember that Open Source operating systems like Linux are acquired for free. (For example, check out products like: Gentoo, Debian, and CentOS to only name three of many)
2. The marketplace realizes that the price of Alpha and Itanium hardware has already dropped significantly compared to VAX
3. OpenVMS is ported to other processor platforms like Intel's x86-64 family.
   This is not as ridiculous as you would first think. Both AMD and Intel have added 64-bit extensions to IA-32 which industry insiders refer to as x86-64 (a.k.a. AMD64, Intel 64, EM64T)
    

bastions of hardcore OpenVMS popularity:

1. Semiconductor Manufacturing
2. Medical (HMOs etc.)
3. Military
4. Intelligence Community (NSA etc.)
5. Telephony
6. Nuclear
7. Banking Industry
8. Investment, Securities, and Clearing
9. Lottery
10. Automobile/Automotive Parts Manufacturing
11. Steel and Aluminum Production
12. Chemical Industry
13. Pulp, Paper, Packaging and Forest Products Industry
14. Glass Industry
15. Pharmaceuticals
16. Textile Industry

Click here for more details.

1.  OSF/1 was a clean version of UNIX produced (initially) by seven companies under a collaboration known as the Open Software Foundation. The big three included IBM, DEC and HP
2. AIX (derived from OSF/1) by IBM
3. Tru64 (derived from OSF/1) by DEC. Compaq, HP
   
   • for some reason we'll never understand, DEC kept changing the name of this product which served to confuse the marketplace. See this list
   • Starts off as Digital OSF/1 for MIPS
   • Alpha versions included:
     • Digital OSF/1 version 3.x
     • Digital Unix version 4.x (a.k.a. DUNIX)
     • Tru64 Unix version 5.x
   • In 1998, DEC was purchased by Compaq and is now called the "Digital Equipment Corporation" division of Compaq
   • In 2002, Compaq merged with HP were HP-UX was king. HP did little to market Tru64 so stopped development and marketing of it in 2004
4. HP-UX by Hewlett-Packard (HP)
5. ULTRIX (by Digital Equipment Corporation a.k.a. DEC) is officially unsupported as of 1999.12.31. This OS ran on MIPS based processors manufactured by DEC.
6. Linux is available free of charge under GPL (general public license) and is distributed and supported by companies like Red Hat and SUSE just to name two of many. See linux.org and distrowatch.com for more info
   Note: contrary to popular belief, there is no actual operating system named Linux. Linux is really just a different Unix kernel with BSD (or GNU) applications tacked on. Read this 'extreme tech' article for more info.
7. Solaris and SunOS by Sun Microsystems
   • Oracle purchased Sun in 2009-2010
8. BSD (Berkley Standard Distribution)
   • www.netBSD.org
   • www.freeBSD.org
   • www.openBSD.org
9. SCO Unix by the Santa Cruz Operation
10. QNX by QSSL (co-founded by Gordon Bell and Dan Dodge of Ottawa)
    • this is not the Gordon Bell of VAX/VMS fame)
    • on April 2010, Blackberry maker RIM announced the purchase of the QNX product line
11. BeOS by Be Inc (which they claim isn't based on Unix but was only influenced by it. However, It supports grep, awk, Bash shell, etc. and is free)
12. Mac OS X by Apple

1. Easier to cluster OpenVMS machines; easier to load balance them (they've been doing it since the early 1980's using the LAT protocol)
   During a 2003-06-xx seminar I witnessed a demonstration where OpenVMS was running in a three-way cluster composed of different hardware architectures (VAX, Alpha, Itanium)
2. Multiple instances of OpenVMS operating systems can run together on the same hardware platform in something known as a galaxy configuration. Different operating system versions are allowed which means that systems may be upgraded with more rigorous testing.
3. The POSIX interface in OpenVMS allows Unix programs to run with little, or no, modification. One popular example of this is CSWS (a.k.a. Compaq Secure Web Server, a.k.a. Apache web server)
4. Many programs written in "C" for Unix can run on OpenVMS with little more work than a simple recompile and link. This is due to the HP OpenVMS Unix Portability Initiative
   This allows valuable products from groups like www.apache.org and www.isc.org to make their way effortlessly into the OpenVMS community.

1. Most Unix clusters only use a failover strategy (so one node is usually doing nothing but waiting). However, Tru64 incorporates TruCluster technology which was derived from OpenVMS. All nodes in the cluster participate in load sharing based upon their individual system capabilities (smaller hosts would participate less)
2. Contrary to popular belief, there is no actual operating system named Unix. Unix is a generic name which means that "Unix style operating systems" appear to have many similarities. They also have many differences. One cool variation is GNU which is a method to get around Unix copyright problems.
3. Contrary to popular belief, there is no actual operating system named Linux. This OS is really just a different kernel merged with BSD (or GNU) applications tacked on.
   https://www.extremetech.com/computing/52018-the-bsds-sophisticated-powerful-and-mostly-free
4. SCO does not own Unix but they do own the source code for the AT&T flavor of Unix. Click www.opengroup.org for more details.