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Posted

I want to be able to offer our students an open source alternative to windows. I am particularly keen on the ubuntu / edubuntu flavours of linux.

 

As i see it, i have three basic options open to me.

 

1. Dual Boot - however, this could be time consuming with constant re-starts to load new OS.

 

2. M$ Virtual PC - is there a way to lock down the image, control exactly what the kids can access, provide access to their home directories. But it's Free!

 

3. VMPlayer and VMWorkstation - Same as above really. But the VMworkstation needed to create the images costs money. But the VMPlayer would mean the image was read only.

 

Also there is the issue with bandwidth with the 2 virtualization methods. I would prefer a networked image that I could update as and when, but the image/ virtualHD would be a couple of gig.

 

How do you get around these issues in your schools? Recommendations, suggestions, experiences greatly appreciated.

Posted

If your machines can run it VMWare will be the least hassle, it's a lot further ahead than virtualpc - but don't even think about trying to run either across a network - it ain't gonna work. You could probably setup an overnight script to reload a snapshot of the clean vmware image - or just lock the linux machine down, it's quite secure.

 

LTSP might be a good choice, but you'll need a server and will need to configure the clients to boot PXE, this might cause issue switching back to windows. - also LTSP can have bandwidth issues with high graphical stuff.

 

Given a server, FreeNX is also an option - a bit more hassle to setup than Ed/Xubuntu LTSP and requires more processor on the server. What you loose in proc usage you save in bandwidth as FreeNX uses a compression and caching system similar to Citrix. The windows machine would run a FreeNX client - think VNC but better. Another downside of LTSP/FreeNX/VNC is that you'll need to run a lightweight window manager - no gnome/kde and certainly no XGL.

 

My prefered method would be to get a Citrix install for windows only apps, ditch XP and run semi-thin clients. This way kids get windows when they need and linux when they need, plus you save on licensing and mainenance once its all set-up. Fairly easy to do, and has enormous benefits, but expect resistance from all sides because its different.

Posted

Forgive my ignorance, i'm not as up to speed with linux / virtualisation as i would like to be.

 

So in theory I could:

Install VMServer - create a server and very basic client image with LTSC installed on. Before rolling out a new windows image across the network during half term, install vmPlayer and copy client image to hdd.

 

Run server image. pupils can then run vmplayer with linux client which could then connect to server allowing me to update the server image at any time. :scratch:

 

Or would it be best to just create the image in vmserver, and copy it out to the machines every time i do an upgrade. Bit of a hastle but at the moment seems the best idea. Most annoying thing is the size.

 

Or did i miss understand LTSC and you can get a version to run on windows and connect to a virtual linux server?

Thanks for the responses so far....

Posted
Install VMServer - create a server and very basic client image with LTSC installed on. Before rolling out a new windows image across the network during half term, install vmPlayer and copy client image to hdd.

 

Yes, but not LTSP, THe LTSP bit is something else.

 

Run server image. pupils can then run vmplayer with linux client which could then connect to server allowing me to update the server image at any time. scratch

 

This will need to be a *very* powerfull server if you have more than a few kids logged in at a time. IIRC the new VMWare product - Virtual Desktop Infrastructure, will do this better. It looks like a true cross platform Citrix rival, but requires ESX farm (money).

 

Or would it be best to just create the image in vmserver, and copy it out to the machines every time i do an upgrade. Bit of a hastle but at the moment seems the best idea. Most annoying thing is the size.

I think this is your best bet

 

 

Or did i miss understand LTSC and you can get a version to run on windows and connect to a virtual linux server?

 

LTSC? LTSP is the Linux Terminal Server Project, nothing to do with virtualisation and AFIK there is no client that runs on windows since LTSP requires a linux kernel running on the client, there are windows clients for VNC and FreeNX which only see 'screenshots' of the linux server, like rdp/citrix ica.

Posted

LTSC? LTSP is the Linux Terminal Server Project, nothing to do with virtualisation and AFIK there is no client that runs on windows since LTSP requires a linux kernel running on the client, there are windows clients for VNC and FreeNX which only see 'screenshots' of the linux server, like rdp/citrix ica.

 

Sorry, typo.

 

Ok, from what you've said i think best option is to create an image and copy to all machines. that being said if i wanted to connect this to the domain so the kids can access their folders would that cause any problems with them not being able to adjust the image. or would it do the changes in memory but not save them.

Posted
They'd still be able to save in the guest image - I don't think you can avoid this, but if you authenticate the guest to the domain, they'd only be able to save in their /home/username directory
Posted

You can set your image up so it connects to the domain and redirects the users home directory to somewhere sensible on your windows network. This is no different than doing it on a real Linux workstation.

 

It requires some tinkering on both ends of the equation though, so you might want to leave it as another project. Small steps, etc. :)

Posted

It's on my try-it-for-real list, but VMWare Server supports taking one snapshot of an image and VMWare Player will run the subsequent VM. When you take an snaphot it essentially freezes the state of the current virtual disk (VMDK) file and subsequent changes are stored in a second VMDK file. Essentially:

 

Current disk = Base VMDK + Delta VMDK

 

You might be able to roll out one inevitably big, but static base image that can be used with a smaller delta. If you're doing minor upgrades, just swap-in a new delta. Or maybe you want several deltas e.g. point the VM config at delta A if you want Programming tools, point it at delta B is you want CAD tools etc. Or replace the current messy delta with a teesy post-snapshot delta to get the VM back to a clean state.

Posted
This will need to be a *very* powerfull server if you have more than a few kids logged in at a time.

 

If you are referring to LTSP, we used to run Athlon 2.2 GHz 1 GB ram servers and these would support 15 thin clients each running OpenOffice and browsing the web. Response time and stability was acceptable. Of course, things are better if you have powerful servers, but our experience has shown that you can basically use any old junk and the LTSP works brilliantly. We ran 6 of these servers, to support our 3x30 seat labs - all obtained on the cheap.

 

With new funding, we are now running 4 x Xeon 3Ghz, 4GB ram servers and it flies. Dual processor servers is the only possible upgrade left for us and hopefully this is on the cards.

Posted
Ok, out of interest. If i use VM server to create the image, and vm player to run the image. What happens if i want to connect to the domain. The machine name is set in vmserver........ virtualisation on a big scale with domain connection seems as though it is going to cause me no end of trouble!

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