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Linux VMs For Everyone
Over at Newsforge, Grant Gross has written an interesting overview of the options available for hosting multiple Linux installations on virtual machines; interestingly, it's not just for those with the big bucks for high-end IBM hardware, though that's surely nice.
In particular, VMware's "undoable disks" are great in this regard.
CEE5210S The signal SIGHUP was received.
Then install linux, no need to buy a new machine.
it's not just for those with the big bucks for high-end IBM hardware
This isn't really new. Slashdot had an article about it a month or two ago. Unfortunately the link escapes me.
After seeing that article, I presented it at work. We now use it to keep the logging facility and services separate from each other, so a break in to one service doesn't compromise the others or the logs.
It works pretty slick.
Having never used ResHat I am positive it also most assuradly sucks too!
Cool! Not only are you allowed to run Linux on your computer for FREE but you are allowed to run 1000 copies of Linux on your computer for FREE!!
Now, 1000 copies of Windows on a machine would cost... $100,000? Nehehe. Linux rocks =P
What are the price/performance ratios for virtual machines? Is it cheaper to run 10 VM's on one 10 times faster machine than just 10 slower machines? Because the VM idea is exactly the opposite of Beowulf cluster, and it doesn't look very cost-effective.
~shiny
WILL HACK FOR $$$
I can't remember my windows days all that well, but doesn't the Microsoft Windows license apply to a single computer??? Wouldn't that mean you can run as many copies of windows, as long as they are on the same computer, as you want?
Who knows? Maybe Micro$$oft did shoot themselves in a foot?
Microsoft and Intel have been squabbling over this very issue recently.
The reason there's a value to virtual machines is because you can't buy half a computer [from reputable vendors!]. If you have four jobs that only require 1/4 of the resources of a modern PC, but they all need different security contexts, you must a) buy four servers or b) buy one server and run 4 virtual machines.
There's probably even some value in a beowulf cluster of virtual machines-- if you want to write and test cluster-based software when you don't have access to a cluster.
I'm a big believer in freedom of speach myself; but it's pretty apparent that between the page-lenthening posts, goatse.cx links and truly sick ASCII art that perhaps some draconian measure might be appropriate. Freedom isn't everything; but boosting the signal-to-noise ratio is.
Strangely enough...
/. joke that has some root in valid practice.
I do test cluster based software... I might have just made the only reference to a running
"Oh my God. This is terrible. This is the end of my Presidency. I'm fucked."; ~ Donald J. Trump
e-genera has some neat dynamically reconfigurable computers that amount to a single-rack, virtualized server farm that can run a customized version of SMPed Linux or Win2k/XP.
The biggest trick the devil pulled was letting lawyers become politicians so they can write the laws.
Can anyone spare a few kilowatts?
Sometimes, I think I need another instance of the OS running when I'm working on 3-4 desktops, with maybe 40-50 apps running concurrently. But then, I think, maybe I'm just working too hard.
Anyhow, We're here, & here, & here, for you, with more coming every day, if you need IT, or just somewhere to hang your hack. Talk about virtual instances/multiplication?, we're like rabbits. Almost everything's GNU now. Don't forget to look here for some really good stuff.
If youre hosting, you cant beat this solution
..)
Folks over at Solucorp
Have made kernel patch and utilites to make this almost painless, as well as some precompiled kernels, (I would laways roll my own but
This as I said kicks for hosting, its not just a chroot, and its not like the jail on BSD, its....well different.
This isnt somethign youre going to do on your desktop machine , its going to allow you to span resources, this is COMPLETLEY different from VMWare etc, for all the yahoos that are gonna say this has been around forveer.
After SEVERLY abusing our test server to hell an back starting 2-1 we are going to be offering hosting in this enviroment , we have clients that want their own playground but dont want the maintenece, some have semi-secure data theyre just no comfortable on a shared solution and cant quite justify a dedicated box, were already slated for 10 clients and with their current traffic and traffic times, they will all play very nicley on the same machine
P.S. LOAD up on the ram , and make sure to use SCSI , Low ram and Ide will work but start to bog under load, remeber you have 10 different Linux installations trying to access the disk at once.....
Sig went tro...aahemmm.....fishing........
It depends. One key thing multi-user systems have which is great is, of course, task switching. Multiple process control. I'm sure that of 10 copies of word running at the same time would run well on a machine that's 10 times powerful than the base, but that's if all 10 copies were maxing out their resources continuously.
Also, If there can be a way of 1 copy in memory of the program/OS itself and multiple copies can be run at the same time without taking up more memory, that would be great too. Sort of like the kernel, it only loads once but services multiple processes. A program that can service multiple users without creating multiple copies.
All in all, maybe 20VM's on a machine 10 times faster might be enough as it doesn't need to scale liniarly unless the machines are completely maxed out. And if the kernel could be loaded in memory once and act as multiple OS's, that'd kick butt too. Sorta like FreeBSD's jail. (Is fbsd the only one to have jail now?)
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ping -f 255.255.255.255 # if only
Remeber the ad for this? It was hilious
..."
... "
A panicking manager type leads police detectives into what appears to be an empty server room. "It's the crime of the century!" the balding, middle-aged, middle manger exclaims over cheesy adventure-movie background music. "Everything's gone!"
"What was stolen?" asks one of the cops.
"Everything," the pointy-haired boss answers, "payroll, R&D, customer records
Of course, our hero, a scruffy-looking geek boy, saves the day. He points to a mainframe in the back of the room, and says, "We moved everything onto that one. It's going to save us a bundle. I sent out an email
But how do you assure decent IO in a virtualized machine? I'd imagine it would be pretty poor with the disk head skipping all over the place. I'm also curious if the processor cache would hold up well.
The holy grail seems to me to be cheap processors and disks hooked up via infiniband.
The article talks about how hundreds, even thousands of OSes can run on one machine. Well, what if the underlying VM architecture, or even the hardware itself crashes?
Now you have hundreds, even thousands of customers mad at you... and all their stuff is on just one machine. Yikes!
Thanks, 'dawg.
just for da sake of journalism
isn't this just user-mode linux?
Did Intel fix the x86 self-virtualization problem with the Pentium and laters? I know that the '386 and '486 couldn't fully virtualize themselves, because it was possible for non-supervisor code to look at certain flags.
A 680x0 (x >= 1) could fully virtualize itself, because the condition codes could be accessed separately from the status register (MOV.B D0, CCR as opposed to MOV.W, D0, SR).
Just curious. Oh, and I think the article got it wrong. They said VM has been around for 20+ years, I believe it's closer to 30+. Any old JCL'ers out there?
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
Somebody set us up the dot bomb.
That could never happen. We use only the best programmers to write the VMs and then test them thoroughly for two, maybe three minutes, sometimes. Talk about bullet proof.
Not a bad start, you can expect a lot of useless (as in not helpful) criticism from some 'special people'. Good luck to you.
Is it cheaper to run 10 VM's on one 10 times faster machine than just 10 slower machines?
Depends how much you pay for rack space.
We went to an IBM presentation on this 6mo ago, which was aimed at marketing types but still pretty interesting. It only takes minutes to image a new server and put it online. I'm guessing that if you ever needed to reboot one it would take seconds.
455fe10422ca29c4933f95052b792ab2
iSeries. (Formerly known as the AS/400).
Up to 31 Linux partitions using the 32 or 64 bit PowerPC kernel, concurrently. Run it on anything from a $20000 model 270 up to the biggest 24 processor machine IBM sells. Available from SuSE, TurboLinux, and RedHat.
I plan to provide "Virtual colocation" based on
UML and (alternatively for people who don't want Linux) VMware for 30$/mo in February.
Physical hardware will be dual 1.6Ghz Athlon MP.
If you are interested in being a beta customer, please contact me.
-alex
Now HOW was this moded as redundant, did the moderator not read the rest of the thread?
"Oh my God. This is terrible. This is the end of my Presidency. I'm fucked."; ~ Donald J. Trump
I just attended a VMware training session at work (a place very fond of "VM" since they invented it about 35 years ago ;-), and it was made very clear that we must have a valid Windows license for every guest vm running M$ Windows of any sort.
--
A former VM "sysprog"
Can someone explain the practical difference between this and *BSD's jail() environment? On a side note, why *doesn't* Linux support jail()?
The first time I knowingly and deliberately used VM was at NCAR, on the front-end machines to the Cray-1 in 1983.
Each user had a VM, with a specific amount of disk, CPU, and memory allocated. Your copy and even choice of operating system -- MVS, CMS -- ran on that virtual machine. So, like they say, it's been around 20 years or more. I say "knowingly and deliberately" because from 76-82, I'd used VM/CMS on our university's IBM 360, which also used VM -- but student users were barred from actually interacting with VM, so it was just there, use it. (CMS stands for "Conversation Monitoring System" -- scary!)
Back then, when I had a choice (i.e. had an application that didn't require the Cray!), I preferred the far less structured environment of our 4.2 BSD Vax 11/750.
For a mainframe, multiuser or server environment where you need control over everything, and records of everything -- VM the ticket. For your desktop, it's a bit much, really. To turn your desktop into a server, hmmm. Not a bad idea to run VM on it, and run various services in their own virtual machines. A bit more secure than a chroot, since even a buffer overflow bug wouldn't be able to get at the other processes -- they're running in a completely different address space and controlled by, well, a different operating system --or at least an entirely different instance of the same operating system configured differently.
But VM itself is hardly news. Plus ca change, plus ca change pas.
Where can we get that hosting? How much does it cost? What is included (IP, bandwidth, etc)?
--- Hindsight is 20/20, but walking backwards is not the answer.
Apparently the email didn't get delivered.
now we need to go OSS in diesel cars
The article a little bit skimps on details, bunching VMware and other things in same category.
;)
VMware, plex86 and bochs are in one category: Real virtualization solutions, allowing you to run any operating system. The level of security these tools provide is very high (guest OS shares nothing with host OS. All access is controlled by virtualization software).
Vmware works (surprisingly) pretty damn good, I haven't had an issue with it behaving any differently from a real OS running on same hardware. Of course, its a commercial solution with associated problems (no source, can't embed, pricey, etc). Its very fast, and reasonable on resources.
Plex86 is same idea as vmware, only Free.
Right now, though, plex86 is in state of disrepair, because lead developer has been laid off from Mandrake, and codebase is in flux. You'll have much more luck with Jan-1-2001 snapshots if you want to actually boot up any OS. Don't know how fast it is, never got it to boot up enough to run tests stably.
Bochs is even lower-level approach to virtualization: it can emulate x86 on any processor. Of course, its dog slow and eats lots of memory (Expect 100x hit on performance).
Other solutions (swsoft, ensim, linux virtual server(LVS)) are a lot closer to jail() system call of FreeBSD. With these, you are running one kernel for all "environments". Security is provided by other means ("root" in the jail has a lot of restrictions on it, such as use of IP addresses, etc).
With many of these solutions, you will run in certain incompatibility problems (root not able to things which it should be able to do, but restricted in jail). Transparency is an issue: for example, even though you don't see other jail's processes, there's still a single PID space, and you can tell which PIDs are running by forking 60000 times and recording which PIDS you get and which ones you don't. Also, user doesn't have full control over its environment, for ex, you can't have your own inittab, etc.
However, these solutions don't have any overhead, very resource-nonintensive (you can run 50 jails on one host with almost no performance impact).
Level of security these solutions provide is very questionable: if there's a jail check missing _anywhere_ in kernel where root access is verified, it will lead to a host compromise.
Note: Of the above mentioned solutions, I only worked with LVS (www.linuxvirtualserver.org), and its the only one that is GPL'd.
User-mode-linux (UML) occupies space in between: It doesn't virtualize the processor, but it has a separate kernel running for each VM, for excellent transparency, and reduced risk: As UML itself runs as non-root, even if a bug in UML implementation is found that would allow to make system call to host kernel, it would still at worst result in single-user compromise on the host. (Unlike LVS/jail where it would lead to root host compromise).
The way it works is following: UML is essentially a "port" of linux to linux. (I.E. linux that doesn't run on bare metal, but uses host's services to implement linux). It traps system calls by application and executes them itself.
Currently performance of UML is spotty (each syscall by application results in 3 context switches on host), but its being worked on at amazing pace. (Thanks Jeff)
Summary:
a) if you need to be able to run 10+ 'guest' environments on a host, look at LVS or jail.
b) if you need to run non-windows guest environments, vmware is your answer.
c) If you need to run 1-10 guest environments, with good security and you have memory to spare, look at UML. Its performance is likely to improve soon.
I plan on providing a "virtual colo" service based on UML for linux-oriented people and vmware for people who want to run Windows on their 'machine'. The idea is to provide service to people who outgrew traditional virtual hosting environments, but not quite ready yet (or don't want to pay) to have their own dedicated server. Pricing will be around 30$/mo.
There's probably even some value in a beowulf cluster of virtual machines
By running a cluster of virtual machines, the VM enviornment can take (RAM/DISK/CPU-CYCLES) and reallocate them where they are needed. It's like a cluster of mixed machines where the simple tasks are always running on the crappy low end machines, and the monster tasks are always run on the souped up high end machines. But you want to run all this on really fast hardware. So you run it on a beowolf cluster. The VM envoirnment can then reallocate real machines to run the VM machines that need the extra resources.
A virtual beowolf cluster running on a real beowolf cluster. Wow. Imagine a beowolf cluster of THOSE!
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
This is not really new info is it ?! There are multiple companiesd out there how have done this and who are making money out of this in the web-hosting market.
This is not even limited to Linux, there are also Sun VMs arround (I've got a SUN VM hosted by NTT/Verio - which works great).
The thing is that this does not always get what you need, if you need direct root access, you won't get it (if it is hosted). I've not really run into these issues, even though I do development on these systems.
cheers.
brrrrrr.
brrrrrr it's cold
on this discussion a lot has been said about VMWARE. i just wish to quickly poit out that VMWARE new licence is redicolously restrictive basically prohibiting any VMware machine to act as a SERVER for any service. Read it yourself if you dont believe it.
The basica idea behind it was to prevent peopel from buying the ""cheap"" 300 USD version and doing virtual hosting but in reality that licence states more than that.
SIncerely
Giovanni Tummarello
www.Wup.it
We dont do commodity hosting, we only host existing clients, or clients we have done development for.
:) , RH 7.2 all current with 2.4.17 (probably rmap-11c tool, ill see)For now this is a limit of the vserver utilities, Backups of your VM root are done from the Root, server that has NO net access. Hosting like this is as I said expensive, but our clients pay for my administration, 300 a month email me if interested.
I am considering putting up another box, for people, a sort of develoment enviroment that we would maintain for these existing clients that want a sandbox aside from their production enviroment, I could possibly hast you there.
Bandwith is limited on that line, it is quite expensive in our area. 10 gigs a month transffer and 5 gigs HD space, on a 1.7 ghz box with 1 gig ram. You get one IP address, all yours
Sig went tro...aahemmm.....fishing........
I've got one of these accounts at webpipe.net. $35/month. 1 static IP. 20GB/month.
The Glass is Too Big: My Take on Things
>main(){for(;;)fork();}
Canonical form is:main(){fork();main();}
--
All people seem to need data processing
From the time Business people had a laptop and a desktop. They were running the same Licence on both, saying
"this was a running session that is the same user as the desktop one, so laptop is considered as a "Backup Copy" that doesn't run at the same time as desktop one"
Now M$ just added a line in EULA.
It takes 40+ muscles to frown, but only four to extend your arm and bitchslap the motherfucker
In theory, that's true, but in theory, resource allocation should be done in the kernel. . .
One thing that makes virtual machines cheaper is that you can combine performance profiles. If you have one application which requires an average of 50, and a peak of 100, and a second application with the same 50 & 100, but the peak is at a different time, then with 2 seperate machines you need 2 of 100. With VM, you can get 1 of 150, because you know that the load will never exceed that, or you machine is not twice as fast, but only 1.5 times as fast. This gets easier and easier to do as you increase the number of applications.