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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.
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.
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 $$$
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.
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.
It's also good for doing things such as running malicious programs in a controlled environment and as an alternative to ICEs.
The biggest trick the devil pulled was letting lawyers become politicians so they can write the laws.
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........
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
Allright. I'm replying to my own message... Hmmm....
Here are some quotes from Windows XP EULA
* Installation and use. You may install, use, access, display and run one copy of the Product on a single computer, such as a workstation, terminal or other device ("Workstation Computer"). The Product may not be used by more than two (2) processors at any one time on any single Workstation Computer.
I am trying to figure out what that means in this case. You can install, use, access, etc one copy of this product on a single computer... Assuming you could set up the VM's to READ from the same install of the software, but WRITE to different dirs - that part should be allright (hey! I'm not saying it would be EASY, but it's doable - Unix does something similar when forking). The other sentence would limit the user to two versions running at the same time (I assume as many as you'd like could be LOADED in memory - ready to be used). I don't know of many hardware that could run multiple copies of windowsXP at the same time (well.. just one - I think it's running Unix though), but with the advances in servers/computers a large company could reduce the windows licensing costs by half!
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!
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.
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.
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