On Tue, Mar 22, 2005 at 12:10:55PM +0800, Tony Mobily IMAP wrote: > Hi, > > >>The Leap from Virtual Host to Virtual Machine > >>XEN, virtual machine monitor-1 > >>Vserver <--- !!! > > > >Linux-VServer ;) > > Woooos... sorry!
in the age of vservers you have to be precise ;) > >>I have already assigned the first one. For XEN, I already have an > >>article. Please have a look here: > >> > >>http://www.freesoftwaremagazine.com/free_issues/issue_04/xen/ > >>(login: author, password:tnmafs) > > > >I skimmed over it, and I think it depends on what > >you plan to do .. because: > > > >about 70% of the stuff 'explained' in this article > >is absolutely true for QEMU, UML, Xen and Linux-VServer > >they basically differ in the level of virtualization > >in the following way: > > > > - QEMU (like VMware) allows to run arbitrary software > > (including a kernel) for one arch on the same or > > even a different arch by utilizing emulated hardware > > and binary translation ... > > - UML or Xen allows to run an operating system compiled > > for the UML/arch or Xen/arch architecture on a (normal > > or specialized) system of the same architecture, by > > 'handling' special/restricted stuff ... > > - Linux-VServer (like solaris slices) allow you to run > > distributions of linux (all userspace) in an isolated > > environment, sharing as much resources as possible, > > nevertheless separated enough to run almost unmodified > > copies of real servers > > OK. > > >so if you plan to make one big article about virtualization > >in general with three or more subsections to introduce the > >different techniques (QEMU, XEN, Linux-VServer), then I > >have no problem writing some stuff for that ... > > OK. that would have been the optimal choice, if we didn't have the Xen > article already... > > >OTOH, if the Xen article is published this way, it doesn't > >make much sense to repeat all the virtualization stuff in > >a Linux-VServer article, and writing an article about > >Linux-VServer stating: "does basically the same, just a > >little faster/more resource efficient, but you are not > >able to have your own kernel (per guest)" is not really > >a good way to do it ... > > True. However, I see Linux-VServer as a different "branch" of > virtualization, where there is only one kernel running. The article on > Xen (which I must admit is not very objective) focuses on > virtualization, where Linux-VServer concentrates on "separation" (only > one kernel is running). let's call it 'isolation' (of course, separation leads to isolation, or was it the other way round ;) > Here is my idea: > > * We publish the article on Xen, taking out this part (which is a > little too nasty and objective): hmm, greetings from Freud? > -------------------------------------------- > It is important not to confuse OS virtualization with so-called > ?application virtualization?, a software technique that in effect > ?bundles? all processes, threads and application related state for each > different application hosted by an OS, into a virtual container. > Application virtualization software vendors, such as Trigence, attempt > to provide balanced performance to each virtual container, by applying > application-specific policies to the OS scheduler. This achieves few of > the benefits of true OS virtualization, the least of which is its > inability to take advantage of new hardware features for > virtualization, and consequently is not considered a serious contender > in the data center > ---------------------------------------------- > > * I tell Eddy (who is writing the first article) to say, right at the > end: why not make some contact between 'Eddy' and myself and we'll talk a little about the different things, I have no problem with a Xen specific point of view and as I said, they are pretty orthogonal IMHO ... > QEMU, UML, Xen and Linux-VServer basically differ in the level of > virtualization > in the following way: > > - QEMU (like VMware) allows to run arbitrary software > (including a kernel) for one arch on the same or > even a different arch by utilizing emulated hardware > and binary translation ... > - UML or Xen allows to run an operating system compiled > for the UML/arch or Xen/arch architecture on a (normal > or specialized) system of the same architecture, by > 'handling' special/restricted stuff ... > - Linux-VServer (like solaris slices) allow you to run > distributions of linux (all userspace) in an isolated > environment, sharing as much resources as possible, > nevertheless separated enough to run almost unmodified > copies of real servers > > * You write an article dedicated to Linux-VServer, which represents in > a way "the other side of virtualization" - we can call it "separation" > not to confuse our readers. I will tell Eddy to use the word > "separation" as well. > > So, the Focus will contain the following articles: > > 1) Introduction by Eddy (covering the bit on QEMU, UML, Xen and > Linux-VServer ) > > 2) XEN (taking out the "nasty" part). This article will only cover > "virtualization" > > 3) Linux-VServer. This article will only cover "separation". You can > say *whatever* you like (things like "Complete virtualization is a > waste of resources", and so on :-) ). You could also explain how the > separation is acheived technically. > Would you be happy with this? well, I'm not very happy about bashing other technologies, especially if they are free and not directly related, I would more prefer to paint a good picture of what is possible with each technology ... > >especially as I think QEMU, UML, Xen and Linux-VServer > >are somewhat orthogonal, which can easily be seen if you > >consider that: > > > > - Linux-VServer can run on UML and probably Xen > > - UML and QEMU can be run on Linux-VServer and Xen > > - Linux-VServer and probably Xen can be run in QEMU > > > >other combinations are thinkable too, and you could even > >build several levels like this extreme example: > > > >PPC64 running QEMU emulating an i386 running a Linux > >system which has one UML instance running Linux-VServer > >which starts a QEMU (on i386) emulating some ARM ;) > > AAAAAAAAAAAHHHHHHHHHH!!!!!!!!!!! but not that unrealistic ... > >well, if you want to give some history/background, about > >the development, then please go ahead, that's nothing I > >could write objectively about .. btw, a good idea would be > >to pay a visit to our irc channel (#vserver @ irc.oftc.net) > > OK, I will try :-) great! > >>Please let me know as soon as possible if you would be willing to > >>write > >>this article! (Grisha, in cc:, offered help as well!). The deadline is > >>a little tight (10th of April), but a short article would be fine as > >>well. > > > >I guess the community can do that easily ... > > > >btw, I would like to forward this email to the mailing list > >([email protected]) if you do not have any > >strong objections ... > > I don't have any objections at all. However, I think it would be better > to decide what the Focus' outline should be, or things can get a little > confusing (too much input can be dangerous if the foundations are not > set...) okay, so this is cc-ed to the ml then ;) best, Herbert > Bye! > > Merc. > > ------------------------------------------------------------------------ > ---- > Tony Mobily > Author of "Hardening Apache" (Apress) > "...this book can save you..." -- Mitchell Pirtle, PHP Magazine 05/2004 _______________________________________________ Vserver mailing list [email protected] http://list.linux-vserver.org/mailman/listinfo/vserver
