Need Info About Virtual machines.
 

Hello to all of you out there.

Recently i got a new project to make a machine to work as server of 30 machines :P to give then internet access (squid), network interaction, apache server for internal network, samba server for other windows machines, firewall, and internal ftp.

Now, the thing is that all the 30 machines don't have HD ( hard disk) so i investigated about Virtual machines from one linux server, but now i'm confuse, how do i make all 30 machines to boot from network? what software is the best for it? Please, all i need is advice :D

The really wird thing is that i read on wikipedia that someone have make a virtual windows xp machine under linux ubuntu? :S is it posible? linux is the server and the virtual machine is windows.

I work with Fedora, so i need a software that run on it please :D

Thanks in advance.

Browse through your Fedora documentation and package manager for PXE and LTSP. There are two tracks that you can use. One is to have each machine be an X terminal with the programs and desktop environment running on the server. Another is to boot up using the PXE server and have NFS shares mounted on a central server. For some apps that need high speed network access it may be better to have the application running on the server accessing large files (like uncompressed video) via an iSCSI connection. For others it my be more efficient running the applications on each machine.

The second method is how a Beowulf cluster may be setup. A central server has the filesystem. Each machine loads in the kernel when they boot. I read an article where a College professor and one of his students created a personal HPC cluster. The used small dual Opteron motherboard, which were mounted on a table. Only one motherboard has a HD and video card installed and they all operated from a single power supply. So for a cluster with 8 motherboards, they saved on the cost of 7 powerblocks, 7 video cards and 7 hard disks. Another advantage as a result was in the savings in power consumption.


http://www.ltsp.org/

Also look in the Filesystem Hierarchy Standard document on the www.tldp.org website. There are a number of static directories that can be shared & mounted read-only. This will allow making changes on a single directory which should ease administration. You will probably have a partition on the server for mounting /home on all of the machines.

I think that your original cause of your confusion is that you have confused the terms 'thin client' with something to do with virtualisation.

Thin client technology seems to meet the requirements that you state, but your investigations seem to have concentrated on virtualisation solutions. LTSP has good resources that you should read.

(This is not a guarantee that you will like the performance of this approach - that is dependant on a number of things that you don't discuss, like the specifications of the server machine (memory, processor) system architecture and what software the client machines run and various loading factors. These could work out to be satisfactory for your installation or not. It is impossible to tell from the information given.)

This seems unnconnected to the main question. Unless maybe I have misunderstood the real objective?

Sorry for lack of information, i will try to explain ib better.

the clients machines have to navigate the internet, use mail smtp, use ftp, and msn, yahoo, aim and others.

The server have 1 GB of ram, HD of 80 GB, procesor AMD Atholn 4000. All clients machine have AMD sempron 3000, 256 MB ram, one lan card of 10/100, and no HD.

I need them to boot from lan, in other words, let the server give them the SO it have. Some sort of remote desktop, for eache client.on desktop for every machine. that the user can customice and save changes, so the next time he use it, it will stay the same :)

In other words, i need a server to give all 30 machine a OS from the network. :)


About it, i want to know if it is posible for a linux server to give all clients a windows OS?

OK, I think that's becoming a little clearer to me now. I thought that you wanted to give the client machines a Linux OS. That's reasonably easy & I have some knowledge about it.

It looks as if you actually want to give the clients something called windows. I know little about this and can't really advise (except, perhaps to say that you will regret it), but, extrapolating from my knowledge of Linux...

The clients (desktop machines) are thin clients and you can make this kind of system (under Linux) with various degrees of 'thin-ness' and the degree of thin-ness has an impact on how much resource your server needs.

1G of RAM on the server is unlikely to be adequate, unless

1. the thin clients aren't very thin at all
2. the utilisation profile is such that the 30 clients aren't in simultaneous heavy usage

and if you run out of ram on the server, the system will really slow down

Your clients will have to have low storage requirements for 80 G to be adequate, but that could easily be the case.

You might also find that you are over-stressing the network hardware. If you have one 10/100 (faster the better) out to a 30 way switch, that could well get a bit busy and, as is well know, once ethernet gets into frequent collisions the throughput plateaus, and plateaus at a lower level than you might expect.

You could have one (two would be better) gigabit link out to to a gigabit switch and run 10/100 out to the clients.
For me, a more appropriate rough spec for the server would be:

1. a quad core processor, with 4G (with possibilty to expand) of ram
2. 3 ethernet 1G out to two gigabit ethernet switches and some kind of net connection (ok, that could be 2 gigabit + 1 10/100 out to an ADSL router)
3. Depending on user requirements something like a 1000G of hard disk, plus another to do a 'hot backup' (controversially, my preference wouldn't be to use RAID....most people would, but I don't, these days, like raid except under very particular conditions)

Ok, thanks salasi :)
i will have to buy some more hardware, but if that is the solution, i will do it :)

One last question, what program (under linux) can i use to make a server to the thin clients?

You might want to go here and there and bury yourself in the documentation.