Linked by Nik Tripp on Mon 2nd Mar 2009 21:40 UTC
SuSE, openSUSE IT solutions companies have been generating lots of buzz regarding thin clients basically since the early 1990s, but have yet to really penetrate into many suitable environments. These relatively cheap computer appliances carry broad promises like energy efficiency, space efficiency, and centralized maintenance and data storage. These claims could sound like the computer industry equivalent of snake oil. Kiwi-LTSP, a combination of KIWI imaging technology and Linux Terminal Server Project, is one open source solution for thin client servers.
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phoenix
Member since:
2005-07-11

What I call Ultra-Thin-Client, you call a Dumb-Terminal. Lets call them UTC for short. As far as I know, there is no vendor offering UTCs, other than SUN with SunRay. All vendor's thin clients are essentially a diskless weak PC with 1GHz CPU and 256MB RAM. Making them unusable for heavy work.


No. Thin-clients, by definition, do not use local processing, memory, OS, or anything. They boot off the network, they load the OS off the network, and configure themselves to act as an I/O hub (send keyboard/mouse data to the server, display graphics from the server). That's it. A thin-client is a dumb-terminal. Period.

Some vendors (like HP, NeoWare, WySE) have "hybrid" thin-clients, which use a local CPU/RAM/OS (usually WinCE) to boot into a local GUI that then runs an rdesktop client. These things are worthless PoS that are over-priced, under-powered, and give thin-client computing (such as it is) a bad name. Once the OS is loaded, and the rdesktop client connects, then it is back to being a dumb terminal. But, yes, the boot times for these things is horrible, as are the graphical capabilities, which is why we stopped looking at them after testing two variations. A standard P2 266 MHz w/256 MB of RAM performed better.

When I talk about one quad core driving 40 clients, I mean one quad core driving 40 UTCs. One user normally requires 1-2GB RAM and 1-2 GHz of CPU. It should be near impossible for one dual core and 4 GB RAM server to drive 30-40 UTCs. Therefore I doubted your claims (misunderstanding).

Of course a dual core and 4GB RAM server would suffice for 30 diskless PCs. That is no doubt, the server would almost act as a file server. Any OS would suffice for that task, even Windows. But I am talking about dumb terminals. There is no way a dual core and 4GB RAM server can drive 40 dumb terminals.


I don't know how many times I can say this: a dual-P3 system with 4 GB of RAM **DOES SUPPORT** 30 thin-clients, where Firefox, Java, OpenOffice.org, and Flash, are all running on the server, with just the display being shot back to the client. WE DO THIS EVERY FRIGGING DAY!! WE HAVE BEEN DOING THIS FOR 7 YEARS ALREADY!!! THIS WORKS!! Get it yet?

So I point out that a quad core can drive roughly 40 SunRays (i.e. dumb terminals). Of course you need lots of RAM for driving 40 SunRays. Each SunRay user needs 256-512 MB RAM on the server which is really good, considering how much memory the user would require if he used a dedicated PC instead.


Which is absolutely horrible! But, you are running Windows, and we're running Linux (for the clients), which is probably where the disconnect is.

Regarding thin client vs diskless PC. I consider them more or less, the same thing. Same, same but different. Both use a rather weak CPU and has little RAM. The diskless PC has slightly better stats, but the thin client has an OS to patch and maintain.As I mentioned, a HP thin client booted in 7 minutes, someone told me yesterday.


No, no, no, no, no, no and NO!!! You do not understand the difference between a thin-client (dumb terminal) and a diskless PC.

In a thin-client setup, 0 CPU, 0 RAM, 0 processing is done on the client. Everything is done on the server. The client is just an I/O hub: mouse and keyboard events are sent to the server, video is sent back to the client. That's it. The local CPU/RAM is only used to boot the client. Nothing else.

In a diskless client setup, you have a standard PC, with a normal CPU, a normal amount of RAM, a normal videocard, a normal NIC, etc. It's a normal PC. The only difference is that there is no HD, CD, DVD, floppy, etc. The client boots off the network, loads the OS off the network, mounts network shares. The OS runs locally, using the local CPU/RAM. Applications are "downloaded" off the network and run locally. Except for the boot process, there's no difference between using a normal PC and a diskless PC.

Do you see the difference yet?

One runs everything on the server, requiring a massive server and an even more massive network, as everything is pushed down the pipes to the display.

The other loads apps off the server, but runs them locally, allowing you to do anything (even play 3-D games) a normal PC can do. But there are no moving parts to worry about, no harddrives to worry about, no OS installs to worry about, etc.

The *ONLY* similarity between a thin-client setup and a diskless setup is that everything is managed from the server. Need to install new software -- do it on the server and all clients get it instantly. Need to upgrade the client OS? Just upgrade the server, and everyone instantly gets the update. Add a user on the server, and they can login from any client station and get their personal desktop.

After a few years you have to upgrade the thin clients/diskless PCs, because they can not handle the new OS and new software versions.


Only for diskless clients. You never *have* to upgrade thin-clients. By definition, nothing is run on a thin-client, it's all run on the server. Hence, the local hardware *DOESN'T MATTER*. Period. The only time you replace a thin-client is when the hardware dies. You don't "upgrade" thin-clients.

Yes, for a diskless setup, where you run apps on the local hardware, you may need to upgrade. However, this is where planning ahead comes in, and you make sure that your initial roll-out can handle the apps you will be using for the next 3-5 years. Or, you find a hardware configuration that is so low that it's basically a disposable appliance (like we did -- at $150 each, we don't bother repairing them).

It is much cheaper to upgrade one server, than upgrade all diskless PCs. It is much cheaper to administer one quad core server, than to administer 40 diskless PCs. In the future, the servers will be dual octo core and have 128GB RAM, then the SunRays will be extremely fast. SunRay are future proof. Diskless PCs are not.


No, no, no, no, and NO! Administering thin-clients and diskless clients *IS THE SAME*. There is nothing to the clients. Everything is done on the server!! They are identical in pretty much every way ... except where the application runs (on the server vs on the client).

For some uses, yes, thin-clients are future-proof. But not for all applications, as the network and server disk are the bottlenecks.

Diskless PCs also suck as much energy as a normal PC


No they don't, as there are no HDs or optical drives sucking power and requiring cooling. And you can build diskless clients using low-power CPUs, chipsets, and videocards.

You can use SunRay over internet. One at work and one at home. You will login into your work environment.


We can do this as well, thanks to NX. It's one of our key selling points to the schools, as they always have access to their school destktop and files, even from Windows machines. Including "suspend" where you login from one machine, suspend the connection, and reconnect from another machine.

Thin-client solutions like the SunRay have their place. But they don't compare to diskless solutions when you leave the realm of simple web browsing and office documents.

Reply Parent Score: 2

Kebabbert Member since:
2007-07-27

Ok, there are still some serious misunderstandings going on. Lets try to establish the definitions. As you start with in math.



"In a thin-client setup, 0 CPU, 0 RAM, 0 processing is done on the client. Everything is done on the server. The client is just an I/O hub: mouse and keyboard events are sent to the server, video is sent back to the client. That's it. The local CPU/RAM is only used to boot the client. Nothing else."

As I have understood it, a thin client processes all software on it's weak CPU with little RAM. A typical thin client has 1GHz CPU and 256 MB RAM, and boots from it's server and downloads all applications from the server and runs the all of the applications or parts of the applications, on it's 1GHz CPU.

Whereas an ultra-thin-clients doesnt process any software at all, it just handles I/O. That is SunRay. The server processes all software. On the SunRay no software is processed at all, it just shows the bitmaps that the server transmits.


You are telling me that this is wrong? You are telling me that any thin client act the way as the SunRay does. Every thin client just shows the picture from the server, and no processing is done on its 1GHz CPU and 256MB RAM? Everything is processed on the server? Is this so? Can you show me a link to a thin client that behaves like this? (Other than SunRay). I have never found any ultra-thin-client other than SunRay.

Either you or my understanding of thin-clients is very wrong. Who is correct? You or me? If you can show links on thin clients working as you described, then you are correct and I am wrong. If you can not show links, then you are wrong and I am correct.





"I don't know how many times I can say this: a dual-P3 system with 4 GB of RAM **DOES SUPPORT** 30 thin-clients, where Firefox, Java, OpenOffice.org, and Flash, are all running on the server, with just the display being shot back to the client. WE DO THIS EVERY FRIGGING DAY!! WE HAVE BEEN DOING THIS FOR 7 YEARS ALREADY!!! THIS WORKS!! Get it yet?"

And you also say that a dual P3 system with 4GB does support 30 thin clients. Where the thin clients does not process any software at all. All software processing is done on the dual P3 cpus. You claim.

I find this very very hard to believe. If it is really is true, then I should look into this solution instead.

I mean, for one user, at least a 1GHz P3 cpu and 512 MB RAM computer is necessary. For 30 users, you would logically need a server with 30 x 1 = 30 GHz P3 and 30 x 512 MB = 6GB RAM. But now you are telling me that it is not necessary. Something is very wrong here. How in earth could it be possible to run 30 users on a dual P3 and 4GB RAM? I dont get it. That config is needed for one single user. How can it support 30 users???

There are some grave misunderstandings going on right now. Even the nick "broken_symlink" is confused. He also believes the same thing as me. He states that a thin-client solution should need a ton of RAM.

We can settle this out, if you post some links to thin-clients. Then I can read about them myself. And study the datasheets. And then I can tell if I have misunderstood the thin client concept.

Reply Parent Score: 2

broken_symlink Member since:
2005-07-06


As I have understood it, a thin client processes all software on it's weak CPU with little RAM. A typical thin client has 1GHz CPU and 256 MB RAM, and boots from it's server and downloads all applications from the server and runs the all of the applications or parts of the applications, on it's 1GHz CPU.


This is what a diskless system is, NOT a thin client, but please read my post on http://osnews.com/thread?351709


Whereas an ultra-thin-clients doesnt process any software at all, it just handles I/O. That is SunRay. The server processes all software. On the SunRay no software is processed at all, it just shows the bitmaps that the server transmits.


This is correct.


You are telling me that this is wrong? You are telling me that any thin client act the way as the SunRay does. Every thin client just shows the picture from the server, and no processing is done on its 1GHz CPU and 256MB RAM? Everything is processed on the server? Is this so? Can you show me a link to a thin client that behaves like this? (Other than SunRay). I have never found any ultra-thin-client other than SunRay.


Phoenix already explained this. He said there are hybrid thin-clients which do have a better cpu, and ram when compared to "ultra thin-clients" like the sunray. But, these are not true diskless systems. Which is what phoenix and I have been talking about.


Either you or my understanding of thin-clients is very wrong. Who is correct? You or me? If you can show links on thin clients working as you described, then you are correct and I am wrong. If you can not show links, then you are wrong and I am correct.


I think your understanding is correct your labels for the different solutions are just wrong, and you also don't seem to understand the third solution completely. A truly diskless system.


There are some grave misunderstandings going on right now. Even the nick "broken_symlink" is confused. He also believes the same thing as me. He states that a thin-client solution should need a ton of RAM.


I never stated anything of the sort. What I said is that as the number of clients in a thin client solution increases you need better hardware for the server. I have no idea what the exact specifications are as I have never used a thin client setup, only diskless pcs.


We can settle this out, if you post some links to thin-clients. Then I can read about them myself. And study the datasheets. And then I can tell if I have misunderstood the thin client concept.


If you don't get it now, I think the only way you will is by actually seeing a setup in action. I'm sure there are guides online how to setup a diskless system. Then you should probably setup ltsp. Finally, compare those two to your sunray, and hopefully then you will understand the difference. Think of ltsp as the "hybrid" thin-client.

Reply Parent Score: 2

phoenix Member since:
2005-07-11

Ok, there are still some serious misunderstandings going on. Lets try to establish the definitions. As you start with in math.

""In a thin-client setup, 0 CPU, 0 RAM, 0 processing is done on the client. Everything is done on the server. The client is just an I/O hub: mouse and keyboard events are sent to the server, video is sent back to the client. That's it. The local CPU/RAM is only used to boot the client. Nothing else."


As I have understood it, a thin client processes all software on it's weak CPU with little RAM. A typical thin client has 1GHz CPU and 256 MB RAM, and boots from it's server and downloads all applications from the server and runs the all of the applications or parts of the applications, on it's 1GHz CPU.
"

That's a diskless client, not a thin-client.

Whereas an ultra-thin-clients doesn't process any software at all, it just handles I/O. That is SunRay. The server processes all software. On the SunRay no software is processed at all, it just shows the bitmaps that the server transmits.


That's a thin-client.

You are telling me that this is wrong? You are telling me that any thin client act the way as the SunRay does. Every thin client just shows the picture from the server, and no processing is done on its 1GHz CPU and 256MB RAM? Everything is processed on the server?


Correct. The very definition of a "thin-client" is "no local processing". All applications run on the server, and just the display is sent back to the client. The "thin-client" is just an I/O hub. It sends keyboard and mouse events to the server, and receives graphical output from the server. They have a bit of RAM/ROM to boot, and to find the server, and to establish the network connection, but that's it. After they boot, they run applications on the server, and just show the display.

Is this so? Can you show me a link to a thin client that behaves like this? (Other than SunRay). I have never found any ultra-thin-client other than SunRay.


See below for the link to Wikipedia.

Either you or my understanding of thin-clients is very wrong. Who is correct? You or me? If you can show links on thin clients working as you described, then you are correct and I am wrong. If you can not show links, then you are wrong and I am correct.


See below for link to Wikipedia.

""I don't know how many times I can say this: a dual-P3 system with 4 GB of RAM **DOES SUPPORT** 30 thin-clients, where Firefox, Java, OpenOffice.org, and Flash, are all running on the server, with just the display being shot back to the client. WE DO THIS EVERY FRIGGING DAY!! WE HAVE BEEN DOING THIS FOR 7 YEARS ALREADY!!! THIS WORKS!! Get it yet?"


And you also say that a dual P3 system with 4GB does support 30 thin clients. Where the thin clients does not process any software at all. All software processing is done on the dual P3 cpus. You claim.
"

It's not a claim. Organise a trip up to Kamloops, BC, Canada, and I can show you it in action in School District 73. We use this every single day, and have done so for 7 years now. Over that time, we have replaced a few servers (dual-AthlonMP with 4 GB RAM; dual-Opteron with 4 GB of RAM), and are in the process of migrating off the thin-client setup to a proper, diskless setup. But we still have 12 schools using the original dual-P3 server setup.

But, as I said before, we are using Linux and not Windows. So the user desktop is IceWM running a small handful of opensource applications like Firefox 2, OpenOffice.org 2, TenThumbs Typing Tutor, TuxPaint, TuxTyping, TuxMath, and the KDE 2 games. We have very few problems with this setup.

We're moving away from this setup, though, as we want to be able to put Linux computers into every classroom, into the library, into the office, into the LAT rooms, everywhere in the school (~100 per elem, up to 700 in the secondaries). And we want to centralise printing, give students more disk storage, and give them access to a full KDE 3 desktop, with more applications. We also want to support CAD, animation, video, 3D, audio, and so forth. Hence, we're moving off thin-client, and to a diskless setup.

I mean, for one user, at least a 1GHz P3 cpu and 512 MB RAM computer is necessary.


For a Windows desktop, probably. For a Linux desktop, a couple hundred MHz and a couple hundred MB of RAM is plenty.

We can settle this out, if you post some links to thin-clients. Then I can read about them myself. And study the datasheets. And then I can tell if I have misunderstood the thin client concept.


A very simple, easy read through the Wikipedia article on thin-client computing (http://en.wikipedia.org/wiki/Thin_client) would suffice. ;) Here's an excerpt from the first paragraph:

A thin client (sometimes also called a lean or slim client) is a client computer or client software in client-server architecture networks which depends primarily on the central server for processing activities, and mainly focuses on conveying input and output between the user and the remote server. In contrast, a thick or fat client does as much processing as possible and passes only data for communications and storage to the server.


There's even a list of manufacturers and devices. That all act like the SunRay.

And here's the article on diskless computing: http://en.wikipedia.org/wiki/Diskless_client

Goes into detail on the differences between the two.

Edited 2009-03-05 16:55 UTC

Reply Parent Score: 2