Creating a school computer lab with edbuntu and ltsp

Mon May 21 14:21:54 UTC 2012

Hi All,

I'm running Edubuntu 10.01 with 10 thin clients in a school.
I started with 3 GB on the server, but when thin clients surf the web with
Firefox (and Flash) they sometimes hanged.
If you need surfing and office applications (OpenOffice Java based) you
need a lot of RAM.
I have solved all my problems installing 8 GB ram on the server.

Giacomo (Italy)

2012/5/21 David Groos <djgroos at gmail.com>

> Building on what Mike says, I first used Edubuntu 8.04 (Hardy) with thin
> clients.  The clients were P3's @900 MHz (I believe was the speed--and
> 256-384 Megs RAM) and the server a Dual Core Xeon @ 2.0 GHz, I think, and
> with 3 Gig RAM and RAID 5.  Things worked great until I used Flash or even
> worse, when I used a java-based app, "CmapTools".  These apps quickly
> brought the server to a standstill--not acceptable.
>
> The next year I upgraded from thin-clients to Local-apps, running Firefox
> and CmapTools as localapps and I was very satisfied with that, except I
> wanted to use some USB devices and there is some strangeness with what
> "local" means with local-apps.  I believe I had upgraded some of my clients
> to P4's but things were mixed, but I had upgraded all clients to 512 Megs
> RAM.
>
> The next year, I moved to fat clients so as to get that local support.  I
> was able to upgrade all my clients to Pentium 4's, with 1 gig RAM.  Over
> that year I found that I didn't want *less than* a P4 running @ 2.2 GHz.
>  This was running Lucid.  Things were great :)
>
> This last school year I've not been in the classroom though am supporting
> 2 teachers who are using these systems and made no changes and all has gone
> well.  Next year I expect I'll be running 12.04 again as fat clients.
>  Since ALL processing is offloaded to the client machines, you no longer
> need server-level hardware, according to alkisg, and you simply use a
> dual-core desktop.  He says in Greece the classroom computer labs use the
> teachers desktop as the fat-client server and that the clients use only 512
> Megs RAM!  Nice.  If you want more detail on this perhaps he could tell you
> his setup though may already have it published somewhere.
>
> Also, I remove Hard drives as well.  I run up to 40 fatclients with a 2.8
> GHz, 2, dual-core Xeon (4 cores) and 6 gigs ram and RAID 5.  I have 2, 24
> port, 10/100 duplex switches that have 2, 10/100/1000 server ports through
> which I daisy chain 1 switch to the other.  The server uses the 2-nic setup.
>
> Good luck,
> David
>
> On May 21, 2012, at 7:42 AM, Mike Biancaniello wrote:
>
> When a user logs in from a thin client, it is as if he/she is logging
> directly into the server.  Any user accts/home dirs that exist on the
> server are accessed via thin client, so it never matters which client a
> student uses.  You can lock down a good amount and you just do it on the
> server.  The experience does not change from one thin client to another.
>
> All a thin client does is log into the server and act like a remote
> terminal.  All applications run on the server, hence the very low
> requirements for the clients.
> Local apps allow spcified apps to run on the thin client, which increases
> the req specs for the clients, but offloads some load from the server.  If
> you have clients that are more powerful, you can run those as 'fat clients'
> where almost everything runs on the client.
>
> As far as a processor, the bigger, the better.
> See the installation guide for server and client specs.
> <http://edubuntu.com/documentation/12.04/installation-guide>
> http://edubuntu.com/documentation/12.04/installation-guide
> Edubuntu 12.04 LTS Installation Guide
> Requirements and Preparation Installing Edubuntu is easy! We try our best
> to explain the installation process in a wa…
>
>
>    - *Processor:* Core 2 Duo or Core 2 Quad as recommended minimum.
>    Simpler CPUs will work, but at a performance penalty.
>    - *Memory:* 512MB for the server itself, and between 256MB and 768MB
>    of RAM per client, depending on the demands of the users. Typically, you
>    would want at least 4GB RAM for 20 LTSP users, and ideally at least 8GB.
>    Note that you can also use local applications (called local apps) to shed
>    some memory usage to the thin clients.
>    - *Disk:* 20GB Depending on options. It's recommended that you keep
>    the /home partition on fast disks for optimal performance, refer to the
>    post-install section in this document for more information on setting up a
>    home partition on RAID.
>    - *Network:* LTSP can be very demanding on local network resources. It
>    is recommended that you have at least 1 gigabit connection to the server
>    for every 15 thin clients, and at least 100mbit connections to the thin
>    clients from your switches.
>
>
> ------------------------------
> *From*: Jeremy Schubert <jschubert at shaw.ca>
> *To*: Mike Biancaniello <mikebianc at aol.com>
> *Cc*: edubuntu-users <edubuntu-users at lists.ubuntu.com>
> *Sent*: Sunday, May 20, 2012 at 9:55 pm
> *Subject*: Re: Creating a school computer lab with edbuntu and ltsp
>
> Thanks for the info Mike, I will create a virtual machine edubuntu server
> to test this all out. But here are a few more initial questions fro you and
> everyone else. And I'd appreciate any documentation links.
>
> 1. Specs for the server? Assume it was hosting 30 thin clients.
> 2. I assume that when a client logs in from a machine, their profile
> (home?) is loaded onto the server so they can move from server to server.
> What is the best way of locking down settings per groups? (For example,
> what programs they can access, what happens when they surf the net, how
> much access they have to modifying desktops and backgrounds and if those
> modifications remain after logging out...)
> 3. Can I run batch scripts (or equivalents) to map home folders and other
> folders/directories for users to access?
>
> Thanks,
> Jeremy
>
> ----- Original Message -----
> From: "Mike Biancaniello" <mikebianc at aol.com>
> To: jschubert at shaw.ca, edubuntu-users at lists.ubuntu.com
> Sent: Sunday, May 20, 2012 5:55:27 PM
> Subject: RE: Creating a school computer lab with edbuntu and ltsp
>
> You really don't need all of the partitions. You can certainly create them
> in the install, though.
> Personally, I prefer to keep the stuff for which I need RAID to be off on
> its own server that just handles that and then use NFS to mount the shares
> (SMB if I must share to windows).
>
> Edubuntu can install the LTSP during the initial install.
> The standard install is to have 2 NICs on the server. One on the main
> ethernet (access to internet or other stuff like printers, shares, etc) and
> one to a private ethernet that hosts only the server and the ltsp clients.
>
>
> You can install the server with only a single NIC, but remember that it
> will answer DHCP requests for anything on that network, so if you have
> another dhcp server, you would have to edit the edubuntu dhcp config to
> only answer for the MAC addresses of the client PCs and ignore all others.
>
>
> The PXE clients don't need any operating system (mine don't even have hard
> drives), but you might need to edit the bios to ensure that the NIC is
> configured to boot "w/pxe."
>
>
> All of the clients will use the credentials on the edubuntu server to log
> in. You can, however, configure the server to use existing domain creds. I
> can't give you any info on setting that up, as I use kerberos in my house.
>
>
> I know that's kind of rambled, but hopefully it will help. I can always
> answer more pointed questions or clarify if requested.
>
>
>
>
> From : Jeremy Schubert <jschubert at shaw.ca>
> To : edubuntu-users <edubuntu-users at lists.ubuntu.com>
> Sent : Sunday, May 20, 2012 at 8:04 pm
> Subject : Creating a school computer lab with edbuntu and ltsp
>
>
> Hello there,
> I'm used stetting up school computer labs in the following fashion:
> 1. A group of client computers running windows xp or 7
> 2. A widows 2003 server with
> - 2 NICs
> - lots of ram
> - a system partition
> - a hidden partition for log files
> - a data partition for users
> - a partition for ISO files and programs that have to eunn from the server.
>
> 3. Workstations joined ro the domain forcing users ro login with domain
> credentials.
> 4. Roaming or
> mandatory profiles.
> 5. Group polocies to enforce certain settings
>
> I'd like to try the same thing with edbuntu and ltsp. So , basically, can I
>
> 1. Instal edbuntu on a box with lots of ram and partitions (raid5?)
> 2. Then install LTSI
> 3. Then star the work stations on PXE mode to connect to the server?
>
>
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