Talk:Virtual machine

message: Does the CLR count as a virtual machine? The CLR is certainly not Intel/Windows specific. kibibu 07:41, 18 October 2005 (UTC)
replies: text: I would say so, in the same way the JVM for java is a virtual machine. Daedae 15:40, 10 October 2006 (UTC)
thread_title: CLR

message: Is SCUMMVM really a virtual machine? I was under the impression that it was just an emulator.
:  The article suggests that emulators can be considered as virtual machines. Dysprosia 07:45, 21 Apr 2004 (UTC)
replies: text:  Which article, Dysprosia? Thanks! Stbey 08:18, 21 Apr 2004 (UTC)
replies: text:  This one :) Dysprosia 08:22, 21 Apr 2004 (UTC)
replies: text:  Sorry, I still don't get it! Do you mean this page, Talk:Virtual_machine? Or SCUMMVM? That page doesn't exist yet. And where does 'it' affirm explicitly that emulators of neural networks can be considered virtual machines? Thanks! Stbey 08:32, 21 Apr 2004 (UTC)
replies: text:  The article, Virtual machine. I don't know about neural networks. Dysprosia 08:40, 21 Apr 2004 (UTC)
replies: text:  SCUMMVM is not related to neural networks--it is an opensource emulator/interpreter that executes the proprietary bytecode used by older LucasArts computer games. -- Bovineone 16:04, 10 May 2007 (UTC)
thread_title: SCUMMVM

message: Question: What do you think: Can a connectionist model,
i.e., a neural network, used to solve some specialized
task (e.g. pattern matching, such as optical character
recognition, voice or face recognition, etc.), running
as an emulation on a digital computer, be considered
to be a "virtual machine" as well?
Stbey 08:37, 21 Apr 2004 (UTC)
replies: text: Found an answer. See underftp://archive.cis.ohio-state.edu/pub/neuroprosethe two files bessiere.innc90.ps.Z . . . . . . Oct  8  1991     31k bessiere.nerves.ps.Z . . . . . . Oct  8  1991    272k,"A Virtual Machine Model For Artificial Neural Network Programming".Stbey 07:19, 22 Apr 2004 (UTC)
thread_title: Neural networks

message: It would be nice if we annotate all of them and perhaps split the list into two or three groups. A suggestion is to take the distinction in the article mentioned above
* Emulation of the underlying raw hardware
* Emulation of a non-native system
Hirzel 14:57, 18 Jun 2005 (UTC)
thread_title: List of virtual machines

message: A good reference on the topic, recently published, is Smith and Nair's book Virtual Machines: Versatile Platforms for Systems and Processes (ISBN:1558609105), which mentions the dichotomy in the article.  However, it calls them process VMs (things that host applications, like the Java Virtual Machine), and system VMs (things that host operation systems, like VMware).
Perhaps this page should be refactored to take this text into account.  Currently, it is one of the major works (excluding papers) on the topic.
--EngineerScotty 03:26, 10 October 2005 (UTC)
thread_title: Good reference source

message: The text says "PVM has become the de facto standard for distributed computing world-wide", however I think MPI (particulary MPICH) is far more common.  The fact that MPI is not mentioned at all is rather suspicious.  PVM has not been officially updated since 1993 and is largely considered to be discontinued. -- Bovineone 18:57, 15 February 2006 (UTC)
replies: text: I've renamed the section to be "machine aggregation" and improved NPOV by discussing both PVM and MPI. -- Bovineone 03:31, 13 April 2006 (UTC)
thread_title:  Parallel Virtual Machine 

message: Hi there. Xen is listed as an Operating system virtualization. However, it is also mentioned in Hypervisor. More generally, the hypervisor article largely applies to what are here called "Operating system virtual machines". What's the difference if any? Thanks. PizzaMargherita 13:39, 16 March 2006 (UTC)
replies: text: The difference, in my opinion, is that several of the entries on hardware virtualization (VMWare, VirtualPC) are referring to things that essentially run on top of another full machine (hardware+OS).  Xen in particular runs directly on the hardware and thus has to have a separate OS installed on it to actually run anything.  that is,  app | guest os | vmware | host os | hardware   versus app | OS | xen | hardware.   Daedae 19:46, 1 May 2006 (UTC)
thread_title:  So what is Xen then? 

message: The article has a section on the "Original meaning", which it says is "much better referred to by using the terms virtualization and virtual servers." Then it gives a separate, distinct definition, the "Hardware virtual machine", which it describes as emulation, paravirtualization, OS-level virtualization, etc. Aren't these the same thing? Wmahan. 22:16, 31 May 2006 (UTC)
replies: text: I agree, I don't see any difference between those two. -- Bovineone 23:00, 31 May 2006 (UTC)

text: On the other hand, it announces "Software virtualization can be done in four major ways:", but offers only 3 entries in the list which immediately follows. --Jerome Potts 04:20, 11 November 2006 (UTC)
thread_title:  Redundant definitions? 

message: Doesn't (for example) Bochs qualify as a VM even though it's classed as an emulator? Where do you draw the line?
--Thejaka 08:29, 28 July 2006 (UTC)
thread_title:  Bochs? 

message: "In computer science, a virtual machine is software that creates a virtualized environment between the computer platform so that the end user can operate software."
--This sentence does not make sense.   Between the computer platform and what exactly??
--You are right, the definition didn't make a lot of sense. The whole "definitions" section was quite confused and imprecise. I have re-written it to be in line with the scientific literature, and have attempted to define the terms clearly. Someone who knows PVM and MPI better than me should check that their description is correct.
I removed Plan 9 (has nothing to do with this) and gCore (which is *hardware*, just the opposite of virtualization).
Heiser 06:44, 21 October 2007 (UTC)
thread_title:  Correct Definition?? 

message: Comments above assert that an (application) virtual machine must be platform independent, and that, for this reason, the environment for executing Visual Basic p-code (for example) would not count as a virtual machine. I do not think this is accurate; such environments have been considered virtual machines for decades. The fact that a given virtual machine is localized in a particular hardware or software environment does not reduce its 'virtualness' (though it can certainly make it less interesting). Most interpreter-based systems, and in particular p-code systems and state machines, can be regarded as defining (application) virtual machines. Platform-independence is of course an important aspect of such systems. But their salient characteristic is reliance on an abstraction layer that hides or encapsulates implementation details. One can define such a layer, and implement its behavior, in either portable or non-portable ways.
The progenitor of virtual machine environments, IBM's CP/CMS, was of course hardware-specific, as are any x86 virtualization efforts; but that's a different topic. Trevor Hanson 06:05, 21 November 2006 (UTC)
replies: text: Hmm, depends on. If you can build an machine without any I/O, there is a good chance to build it without any annoying stories about portability. In fact, I/O is mainly hardware, mainly difficult to emulate, to be virtualized. When I programmed the Pascal Microengine (hardware built P-Code), I found a lot of difficulties to catch its registers. Lots of trial-and-errors were needed, but finally I got it. From my feeling, the real I/O is the point to catch a VM. Programming a VM/370 was easy, when you worked with an IBM's standard like 3780, etc... To build your own device, was then a challenge. Finally, I think, that IBM did make a good job then, helped us, helped the community, and the community helped us, like we tried to help the community. Other times perhaps. In fact, I probed some virtual P-Code machines (even on /370) and CDC6600). It worked good on all machines (not so good on the CDC6600 due to lacking fastness) but the I/O is really weak.
I looked into the Source (port from Waterloo to IBM, CP/M, CDC, DEC, Microengine) to port this whole or part of stuff. In fact, you are basically right: P-Code is a virtual machine but from my experiences leaks P-Code from real devices. These were too virtual. Nonetheless, Niklas Wirth defined his machine very good, very small, and I learned to build a compiler-compiler based on his books in the 70ths... Was quite right nice then... 46.115.35.3 (talk) 11:12, 20 April 2013 (UTC)
thread_title:  Virtual machine and portability 

message: I just reverted a change that removed this text: The application is run on the computer using an interpreter or Just In Time compilation with User:Hackwrench's comment "A virtual machine is fundamentally different from an interpreter." However, the cited example (Java VM) is implemented with an interpreter, as have been many other VMs such as Smalltalk and p-code platforms.
This is of course a different use of the term virtual machine from the one most typically used today (hence the label "application virtual machine"). However, for decades the term has been applied to abstracted platforms like those just mentioned. I think that this issue isn't fully addressed in the current article text; but the topic should probably be discussed here before removing text. Trevor Hanson 19:01, 5 February 2007 (UTC)
thread_title:  VMs and interpreters 

message: I tried to install VMWare workstion on fedora Core 6, It cannot open because there is a xen file missing how do I correct this problem—The preceding unsigned comment was added by 66.176.27.91 (talk • contribs).
:Wikipedia is not suitable for asking technical support questions. -- Bovineone 16:06, 10 May 2007 (UTC)
thread_title: VMWare workstion on fedora Core 6

message: Perhaps a section (in layman's terms) explaining what VM's are for and perhaps a paragraph or two given a simpler explanation as the article is rather technical. 89.240.13.111 18:51, 3 July 2007 (UTC)
thread_title:  Uses 

message: I just undid the change someone did (they replaced the TrustZone reference with one to Jazelle).  Jazelle provides support for executing Java bytecode, which is a form of language support, not VM support. TrustZone provides a (very limited) form of system virtuzliation (only a single VM).
-- Heiser (talk) 23:04, 30 January 2008 (UTC)
thread_title:  ARM 

message: I think the page should be updated with references to Microsoft Hyper-V technology shipped with Windows Server 2008.
213.203.130.231 (talk) 08:46, 10 April 2008 (UTC)
thread_title:  Microsoft Hyper-V 

message: As usual with compsci vs. market, the article covers two different - but overlapping - topics. I've never ever heard in compsci that "machine" should refer to "computer environment", but instead to "processor", "CPU". Now we have a classic computer confusion, one real academic meaning, well defined and practical, and a fuzzy market meaning covering anything that entails at least partial replacement of some bytes of code here and there before executing the executable... Now, if accepting the marketroid fuzzification as "virtual machines", what is it in a normal jump address relocation performed at ELF loading, that makes the ELF-loader not being a "virtual machine"? If accepting non-academic definitions on this-or-that compsci concept, then we'll end up in a situation when "virtual machine, anything is a virtual machine"; not very helpful!
Now, my compsci whining aside, the article should be parted into virtual machine, and environment virtualization in the long run. We should try to find and document the original definition, and reflect around deviant meanings and market buzz "meanings", in order to treat the topic more concizely. In the List of virtual machine software the subsection OS-level virtualization software does absolutely not belong. The subsection is good and fine, but should be elsewhere to not cause confusion. It might occur that the two meanings are so intertwined that the article can't be split into two, but either way, the contents become more clarified. Said: Rursus ☻ 06:30, 6 May 2008 (UTC)
thread_title:  Two separate meanings 

message: Could a VM application let me run a virtual OS but not to just interact with the real mode os to let someone use older programs they find easier find easier to use but to morelike let yu experiment with that OS without making changes to the real OS apps and create a more closed circle program? Melab-1 (talk) 18:48, 10 August 2008 (UTC)
replies: text: I am not sure of your meaning.  Do you mean, 1. that you wish to use real-mode in any or all environments, or 2. that you wonder if a virtual machine can handle real-mode apps? - KitchM (talk) 21:13, 26 July 2011 (UTC)
thread_title:  Does a VM have to interact with the Platform 

message: What's the difference between a register-based VM and a stack-based VM?  —Preceding unsigned comment added by 70.247.165.213 (talk) 20:39, 30 August 2008 (UTC)
thread_title:  Registers versus stack? 

message: One of the links listed at the bottom of the article leads to what Firefox declared as a "known attack site." The google safe browsing diagnostic lists it as having found malicious software on the site, even within the last 90 days.
I would recommend whoever is editing this article to remove the link or replace it with another link. It would be rather unfortunate for an unsuspecting user to stumble upon the site only to get some malware in their machine.--NWalterstorf (talk) 22:52, 21 June 2009 (UTC)
replies: text: Done, the site had no releveant info, just the download of a few outdated Virtual Machines, clearly not appropriate for the article. SF007 (talk) 00:46, 22 June 2009 (UTC)
thread_title: Known attack site?

message: Quoted from the top:
...limited to the resources and abstractions provided by the virtual machine—it cannot break out of its virtual world.
Should it be perhaps noted that however due to security flaws, it is known that you can break out of some vm situations?
86.44.145.170 (talk) 23:57, 28 August 2010 (UTC)
replies: text: Perhaps the issue that the article is attempting to address is the definitive or ultimate or ideal application.  It is not about security or flaws in application.  There are always exceptions. - KitchM (talk) 20:53, 26 July 2011 (UTC)
thread_title:  Breaking out of vm 

message: That is a wicked cool concept. I never imagined such a thing.  —Preceding unsigned comment added by 72.187.199.192 (talk) 19:13, 20 November 2010 (UTC)
thread_title:  Can I say "Holy Crap"? 

message: Subj  — Preceding unsigned comment added by 178.95.136.216 (talk) 06:14, 3 June 2011 (UTC)
thread_title:  Add [[OCaml]] to "List of virtual machine software"? 

message: Sadly I did not find any information about the history of Virtual Machines. My superficial knowledge says it started with IBM mainframes, but I have no detailed info or sources for this. Anyone who knows more - please insert it in the article. --Bernd.Brincken (talk) 23:22, 16 January 2013 (UTC)
thread_title:  History of VMs 

message: We currently have :Category:Register-based virtual machines and :Category:Stack-based virtual machines, but the difference is not explained in the article. -- Beland (talk) 06:12, 5 July 2013 (UTC)
thread_title:  Register vs. stack-based 

message: I updated the definition in the lead - the prior version seemed to suggest that a VM was just software, although later the article mentions hardware virtualization.  The original definition seems to be thinking of .net or Java.  The difference between a VM and an emulator should be mentioned somewhere, perhaps in the lead, if anyone can figure it out. Peter Flass (talk) 14:33, 18 July 2014 (UTC)
thread_title:  Virtual machine vs. emulator. 

message: Hi.
Do we really need the "Hardware virtualization disaster recovery" section? It looks like overkill for this article that is supposed to provide an overview only.
Best regards,Codename Lisa (talk) 08:13, 4 September 2016 (UTC)
thread_title:  Hardware virtualization disaster recovery