6 ms·

No, he's right. Containerisation is distinct from virtualisation. Virtualisation shares some areas with Emulation, but it's essentially passing CPU instructio

by dijit 3y ago

No, he's right. Containerisation is distinct from virtualisation. Virtualisation shares some areas with Emulation, but it's essentially passing CPU instructions to the CPU without translation from some alternative CPU machine language. The difference here is the level; in descending order: * Containerisation emulates a userland environment, shares a OS/Kernel interfaces. * Virtualisation emulates hardware devices, but not CPU instructions; there are some "para-virt" providers (Xen) that will share even a kernel here, but this is not that. * Emulation emulates an entire computer including its CPU

lxgr 3y ago
Note that these aren't necessarily layered: You can virtualize with emulation, but you can also emulate without virtualization, which is what e.g. Rosetta does on macOS, or QEMU's userland emulation mode.
hnlmorg 3y ago
I don’t think you’ve read the comment chain correctly because you’re literally just repeating what I just said. Though you make a distinction between virtualisation and emulation when in fact they can be the same thing (they aren’t always, but sometimes they are. It just depends on the problem you’re trying to solve).
- dijit 3y ago
  >> The whole point of virtualization is you're running as close as possible to directly on native hardware. That's literally what makes virtualization distinct from emulation for VMs. > You’re thinking of containerisation. no.
  - hnlmorg 3y ago
    They edited their post. If you look at the comments others have made, you can see their original comment was much more ambiguous
    - dijit 3y ago
      Is there a way to see original comments?
      - hnlmorg 3y ago
        Unlikely. It’s too recent for Wayback machine to cache. Their post was ostensibly the same but much more vaguely worded. And if you say “virtualisation is about being as close to the hardware as possible” without much more detail to someone else who talks about wanted to run a VM with a different guest CPU, then it’s understandable that people will assume the reply is mixing up virtualisation with containerisation since there’s nothing in virtualisation that says you cannot emulate hardware in the guest. Whereas containerisation is very much intended to run natively on the hardware
      - olliej 3y ago
        who's post was edited? If they're referring to my original one, then there's only one possible edit I made, because I recall making a comment today that was missing a word, but I updated that instantly so there were no comments or anything, or really likelihood anyone had read it prior to my comment. My "edit" that now has to be an additional comment is at https://news.ycombinator.com/item?id=39061507 https://news.ycombinator.com/item?id=39061507 - I'm curious if you agree with my justification on treating virtualization is meaning explicitly non-emulated these days. From your other comments it seems you do agree with me, but I'd like to know how you feel about the rationale. In response to the editing comment made, my rule for editing or changing comments is that if it's not an instantaneous edit, then the edit should be marked. In response to this thread (the whole thing, not just the one leading down these branches) I did write a stupidly long addendum but spent so long trying to find old marketing material I then couldn't make the edit \o/ My more careful rule about editing is that if someone has replied to a comment, I won't change the text that they replied to, unless the confusion is something very simple like a missing "not" or something where the original text was clearly wrong, and I'll generally do some variation of " .... [edit: not] ...". Otherwise I try to do it as adding additional text with a note saying the new text was added. I find silent edits incredibly annoying, as it means you can't tell if/what has changed in a comment you replied to, and it allows for people to exhibit some really screwed up behaviour. Basically along the same lines as people brought up when apple added editing/deleting to iMessage, where the original betas I think didn't show edits/deletion had occurred, nor what had been changed. I don't think it's reasonable in this day and age for sites like HN to not provide an edit history for comments.

by dijit 3y ago

lxgr 3y ago

Note that these aren't necessarily layered: You can virtualize with emulation, but you can also emulate without virtualization, which is what e.g. Rosetta does on macOS, or QEMU's userland emulation mode.

hnlmorg 3y ago

I don’t think you’ve read the comment chain correctly because you’re literally just repeating what I just said. Though you make a distinction between virtualisation and emulation when in fact they can be the same thing (they aren’t always, but sometimes they are. It just depends on the problem you’re trying to solve).

dijit 3y ago
>> The whole point of virtualization is you're running as close as possible to directly on native hardware. That's literally what makes virtualization distinct from emulation for VMs. > You’re thinking of containerisation. no.
- hnlmorg 3y ago
  They edited their post. If you look at the comments others have made, you can see their original comment was much more ambiguous
  - dijit 3y ago
    Is there a way to see original comments?
    - hnlmorg 3y ago
      Unlikely. It’s too recent for Wayback machine to cache. Their post was ostensibly the same but much more vaguely worded. And if you say “virtualisation is about being as close to the hardware as possible” without much more detail to someone else who talks about wanted to run a VM with a different guest CPU, then it’s understandable that people will assume the reply is mixing up virtualisation with containerisation since there’s nothing in virtualisation that says you cannot emulate hardware in the guest. Whereas containerisation is very much intended to run natively on the hardware
    - olliej 3y ago
      who's post was edited? If they're referring to my original one, then there's only one possible edit I made, because I recall making a comment today that was missing a word, but I updated that instantly so there were no comments or anything, or really likelihood anyone had read it prior to my comment. My "edit" that now has to be an additional comment is at https://news.ycombinator.com/item?id=39061507 https://news.ycombinator.com/item?id=39061507 - I'm curious if you agree with my justification on treating virtualization is meaning explicitly non-emulated these days. From your other comments it seems you do agree with me, but I'd like to know how you feel about the rationale. In response to the editing comment made, my rule for editing or changing comments is that if it's not an instantaneous edit, then the edit should be marked. In response to this thread (the whole thing, not just the one leading down these branches) I did write a stupidly long addendum but spent so long trying to find old marketing material I then couldn't make the edit \o/ My more careful rule about editing is that if someone has replied to a comment, I won't change the text that they replied to, unless the confusion is something very simple like a missing "not" or something where the original text was clearly wrong, and I'll generally do some variation of " .... [edit: not] ...". Otherwise I try to do it as adding additional text with a note saying the new text was added. I find silent edits incredibly annoying, as it means you can't tell if/what has changed in a comment you replied to, and it allows for people to exhibit some really screwed up behaviour. Basically along the same lines as people brought up when apple added editing/deleting to iMessage, where the original betas I think didn't show edits/deletion had occurred, nor what had been changed. I don't think it's reasonable in this day and age for sites like HN to not provide an edit history for comments.