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VMS Questions

Charlie Snowden
Occasional Visitor

VMS Questions

I am new to OpenVMS. I am reading as much as I can so I can apply for various VMS positions. I need help answer a few VMS questions. I can't seem to find the correct answers. Please Help!

Thanks Charlie





Respected Contributor

Re: VMS Questions

Unfortunately the questions you are asking do not have short nor simple responses. Any site that is asking this type of question will require people with vast experience and knowledge of OpenVMS. Since you can not respond to these, you are really not qualified to perform the tasks required of those jobs. Perhaps the purchase of a small and inexpensive system upon which you can experiment would be a better short term solution. In this fashion, you can learn the answers to the questions listed directly.

You can also refer to the documentation set at the following link:


Robert Gezelter
Honored Contributor

Re: VMS Questions


First, let me welcome you to the ITRC OpenVMS Forum.

With regards to your question, I must concur with Dan, you want far better than book knowledge to go into an interview with these straightforward answers.

I speak from experience, having assisted quite a few clients over the years with interviewing. Candidates that were "casually" prepared for questions did themselves a disservice. When the surface question was answered, and the followup question was badly handled, it was fairly obvious that there was not a thorough understanding of the concepts.

I am not speaking of "gotcha" type questions. All of us, myself included, need to constantly dig into the reference set to check information. That is what professionals do.

If this is a moderate to long term goal, get a system (emulated will do), and a copy of the distribution kit under the Hobbyist program (see http://www.openvmshobbyist.org) and get some practice time running your own OpenVMS system.

- Bob Gezelter, http://www.rlgsc.com
Jan van den Ende
Honored Contributor

Re: VMS Questions


Welcome to the VMS community and the VMS forum!

Now for your questions, the short and simple answers:
It works, it is VERY robust and VERY well tested; and you just believe those that have used it (specifically clustering, since 1984).

Now, if you are interested in the "how":
- booting from the same device is by using different ROOTs, and the answer for :
- file system integrity: the Distributed Lock Manager
- systems communicate with each other by SCS (SystemsCommunicationServices), a special protocol at a rather high interrupt level
- any boot device (FC as well) is specified
in the boot command
relevant specific info (if needed) is in the system root in data that is used by the early bootstrap.

--- If you are really interested in the details of these "how"s, you will have to take a number of multi-week courses...

... and even after 30 years, I _STILL_ am learning more detail...

For now, it will mainly be "believe it", and any specific detail you really need, dig deeper into that.

Once again: WELCOME on board!


Have one on me.

Don't rust yours pelled jacker to fine doll missed aches.
Honored Contributor

Re: VMS Questions

Here are some follow-on questions that you'll potentially be asked, and (in fairness) If you don't know the answers to specific questions, indicate which manuals or resources you would review to gain these details. And yes, the first four sections here do use your list of questions as the starting point for the discussion.

1a. What is the directory at the top of the cluster common rooted directory structure?
1b: what logical names are used?
1c: what are the settings used for concealed rooted logical names?
1d: Describe the aliases, and the DCL commands used to establish them?

2a: What are the core DCL commands a system manager uses when verifying and maintaining file system integrity?
2b: what are two system integrated products that increase integrity for RMS and for RAID-1?
2c: How do you convert from the older volume structure to the newer volume structure?
2d: What are the trade-offs with this volume conversion?
2e: What is a typical command to archive a complete disk volume?
2f: What is the sequence for archiving a complete system disk?

3a: What I/O buses support these communications?
3b: Describe the advantages and limitations of multi-host SCSI?
3c: Describe what happens when connectivity is lost?
3d: Describe setting up VOTES and EXPECTED_VOTES?
3e: What is quorum, and how is it calculated?

4a: Describe how to access and use SRM?
4b: Describe how to access and use EFI?
4c: How do you use BOOT_OPTIONS?
4d: Name three ways to specify and use boot flags?
4e: What are zones?

5: how do you migrate among architectures?

6: what commands are used to manage LMF and software licensing?

7a: describe how an application crashes in detail.
7b: describe how OpenVMS crashes in detail.
7c: What commands are used with a system crash?
7d: An application crash?

8: What are the four modes that a DCL procedure can execute in, and describe each?

9a: What is GNV?
9b: describe how to install and configure GNV
9c: How to you manage the C RTL settings?
9d: Compare and contrast GNV pipes and DCL pipes?

10: Describe the system startup path in detail; what are the procedures, tools and directories used, and how to manage it with the startup procedures and with the system management utilities, and how to troubleshoot it.

11: Describe how to acquire and load VMS patches.

12: describe the user login and system-wide login.

13a: Describe OpenVMS system security, including UICs, ACLs and related mechanisms.
13b: describe auditing and alarms, and how to configure and how to process audits and alarms.

14: Describe how to connect VMS to LDAP for external authentication.

15a: What web sites and forums and resources are available with VMS information?
15b: Which of these resource sites that are directly running VMS?

These questions strictly off the top, and might arise in conversations, should I be looking to hire a VMS system manager. (No; I'm not. Sorry.)
Bob Blunt
Respected Contributor

Re: VMS Questions

Charlie, while I do agree with all the other responders my experience helping with interviews has been exactly the opposite. I've spent hours prepping an interviewer and/or manager just to have them consider the advice given as far too detailed or in-depth for their interview. When I tried to explain in non-VMS terms the need for the knowledge I got blank stares and slack jaws. In the end our "committee of VMS-savvy" consultants were asked to concoct a questionnaire that was supposed to weed out the wheat from the chaff. And...it fell right on it's face.

Your questions are far from general and imply that you've read enough to get beyond the simple issues. I will admit that my experience leans toward some simple, almost one-sentence answers that you could use as valid answers for an interview by a single recruiter or manager. If, however, you happened to experience a very VMS-centric shop then you might find the one liner answers woefully lacking.

For instance, question one? While it might be considered flippant you have the "right" structure, a wrong (or unbootable) structure and one that works but isn't "right" either. There's just too much "under the sheets" that would take volumes of description and definition that still left you with many more questions than answers.

As nice as it might seem OpenVMS isn't really the sort of operating system you can just assimilate from 'book learnin'. You can certainly learn a LOT with the right training and education but there will still be some huge gaps. If you're interested you might consider finding an Alpha on e*bay or Craig's list and starting with Hobbyist licenese to learn about it. You should be able to setup a single-node cluster to get some ideas which should generate further questions. Unfortunately you probably still won't be able to give accurate, detailed answers for any of your questions but that might not keep you from being given a job in the OpenVMS space. There just aren't enough shops that have enough VMS focus to really know casual answers from "knows his stuff cold" responses.

Sheldon Smith
Honored Contributor

Re: VMS Questions

As for getting started, in addition to finding used hardware, there are Alpha emulators available you can download and run. Regardless of whether hardware or emulator, you still would need a Hobbyist license (and possibly the operating system media).

For what it's worth, I have had good experience in the past with the PersonalAlpha for Windows Freeware http://www.stromasys.ch/hardware-virtualization-solutions/charon-axp/download-personalalpha/ emulator. As I recall, it emulates a 3100. Hmmm... I wonder if three could be set up as a Local Area VMS Cluster?

Note: While I work for Hewlett Packard Enterprise, all of my comments (whether noted or not), are my own and are not any official representation of the company.
If my post was useful, click on my KUDOS! thumb below!