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

""A thin-client has very little local processing power, and no local OS. It's basically just a terminal. Everything is run on the server, and just the keyboard/mouse input and display output is handled by the unit."


As I have understood it, all thin clients have a weak CPU and small RAM. I only know of SunRay that is ultra thin and just handles I/O. No other vendor does this, they all handle a small Operating System in the background. They are just essentially a weak diskless PC.
"

What you are calling "ultra-thin-client" is just a dumb-terminal.

" "For Linux setups, 1 dual-core PC with 4 GB of RAM can handle 30 clients, so you should be able to handle a lot more than 40 on a quad-core. Although you're mainly limited by network bandwidth than server CPU power."


Wow! That sounds good! But I wonder, have you experienced this performance by yourself or have you only read marketing about this?
"

I've been managing thin-client and diskless setups for over 7 years now, I'm not some marketing droid. Do a google search for "Linux in School District 73 Kamloops" for the details.

There's just no comparison between thin-client and diskless setups ... unless all you are doing is basic web browsing and office documents. If you want to do anything beyond that, or anything with audio, video, or even just animation, you can't do it with a pure thin-client setup. There's just not enough network bandwidth to do it well.

You see, one client runs Windows XP + MS Office + Powerpoint + etc at my company. This uses at minimum 1GB RAM and a CPU at 2GHz on a single computer, right?


There's the difference. We don't use Windows for our clients. It's all Debian Linux, with the occasional Win98/WinXP in VMWare Player.

I have problems seeing how you could run 30 of these work loads simultaneously on one server with 4GB RAM and one dual core CPU. Even if you skip Windows I fail to see how one server can run 30 clients on 4GB RAM and a dual core CPU. Because, that is what is needed for one user. And you can not stuff in 30 clients into that.


You've obviously never done anything with Linux, then. You can easily handle 30 thin-clients on a server with dual-P3 1 GHz CPUs, 4 GB SDRAM, and 1 400 GB IDE drive. We do it all the time in our elementary schools. And we have just under 50 of those, each with a lab of 30 computers that get used almost non-stop everyday.

However, that's only for basic web browsing, the odd flash/java game, some educational typing games, and openoffice.org. We quickly hit the "network is the bottleneck" issue when schools wanted to do more than just surf the web and type letters.

We're in the middle of a migration to a diskless setup (12 elementary schools left), using $150 "computing appliances" and now they can do pretty much anything a normal computer can do ... but without the hassle of local harddrives, local optical drives, local floppy drives, local OSes, local software, and so on.

We've also migrated 6 high schools to Linux diskless setups, for everything (labs, library, office, admin), with plans to move the other 4 over this summer.

Actually, I have looked somewhat into thin clients, and I strongly suspect you have no idea what you are talking about.


Considering I've been working with them for over 7 years, and have found them to be pretty useless, I'd have to disagree. ;)

" "We looked at these, and units from IBM, NeoWare, HP, and others. They just aren't worth it. For roughly the same price (new, < $150 CDN), you can get a slimtop case, PSU, motherboard that supports 2-4 GB of RAM, a 2 GHz AMD Sempron CPU, onboard nVidia graphics, gigabit NIC, 7-channel sound. Virtually silent (2 small fans). But few limitations on what you can do with it. Want full-screen video? No problem. Want 3-D games? No problem. Want surround sound? No problem. And it won't saturate a 100 Mbps network to run an entire school (~100 PCs in the elems). The only time the network is hit is when loading programs ... once they are loaded, they run on the local CPU using local RAM."


Maybe you didnt read my first post? Where I gave arguments to why I think ultra thin clients are superior to thin clients (because they are just like a diskless PC). You are describing a diskless PC.
"

Exactly! A diskless PC setup is far superior to a thin-client setup.

The reason I dont like diskless PCs are because they are just like a PC, but without a hard disk. How many sys admins are required for PCs? One sysadmin for each 30 Windows PC? They need maintenance all the time. You need to patch them all the time. Viruses. etc.


Nope. Because they don't have harddrives, they don't have local OSes to worry about. No software patching, no viruses to clean up, no onsite technician required. If there's a problem, you swap out the PC with a spare, edit the DHCP config to allow it to boot, and you're done. Less than 5 minutes to fix a problem. And the only problems to worry about now are hardware related. And with only 2 fans having moving parts, hardware issues aren't that common.

For 19.000 SunRay, you only need 38 sysadmins worldwide.


For 15,000 students, 1600 staff, and around 6,000 diskless PCs, we have 6 school techs, 3 Unix techs, 1 hardware tech, 1 electrician, 1 video conferencing tech, and a couple managers. ;) We've actually reduced the number of school techs since moving off thin-client and onto diskless setups.

This is only possible if you can decrease the work labour very very much. This is not possible with a diskless PC or thin clients.


This most definitely *is* possible with diskless PCs.

Also there are huge energy savings with 4 watt SunRay. One bank saved 94% of their energy bill.


That one I'll give you. Thin-clients do use a lot less energy than full-fledged diskless PCs. However, you don't have to use power-hungry components in diskless PCs. I don't have the numbers for our systems, but they are very low. We use Sempron CPUs, onboard everything, and 250 W power-supplies. They're also configured to shut-off automatically at night, and power-on just before people show up. Compared to the P2/P3/P4 systems they're replacing, they're very green.

The only thing you can not do with ultra thin clients SunRay is playing full screen video (unless you install some software). For work and programming, they are perfect. SunRay has as much performance as the server, they dont run software themselves. If you need more performance, upgrade the server. And SunRay never break, the MTBF is 22 years. If they break, you just plug in a new one. That takes 1 minute and you are back where you were.


Like I said, there are situations where thin-clients make sense. But once you want to go beyond dumb-terminal applications, simple web browsing, and office documents, they just don't cut it. Diskless setups give you all the manageability of a thin-client setup (no local OS, upgrade the server and all the clients get upgraded, just swap hardware when there's an issue, etc) but with all the power of a local PC.

Edited 2009-03-04 17:25 UTC

Reply Parent Score: 2

Kebabbert Member since:
2007-07-27

Ok, we are missunderstanding each other. That is why I suspected you didnt know anything about thin clients.





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. SunRay is unique in that is a true UTC. It is a graphical variant of the dumb text terminals. But you can run Windows/Linux/Solaris with VMware and RDP on SunRay.





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.

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.





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.

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. Worst case, you have to upgrade them all (very expensive), or worse, ditch all diskless PCs and buy new ones. With SunRay, you instead upgrade the server and at once all the SunRays have been upgraded. You can always use your SunRays, they never need to upgrade. Use them for 22 years, if you wish. They always handles the latest OS and newest software excellent. 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.

Diskless PCs also suck as much energy as a normal PC. Compare that to 4Watt SunRay. Say you have 1000 diskless PC each using 100 watt. That is 100,000Watt. With SunRay, that is 4000Watt.

You have no serious performance with diskless PC if you need to do say, a heavy compilation. With SunRay, you have as much power as the server has. A server will always be much much more powerful than a diskless PC or thin client. If you are alone on the server, then all it's powers is yours.

The only thing you can not do with SunRay, is high bandwidth graphics. You can watch movies at 500x500 windows without lagg. But that is graphic intense, compared to ordinary office usage and software development. For all other uses than watching movies, SunRay does it excellent. Many SunRay servers dont have any graphic card. The server generates bitmaps in RAM and sends to each SunRay. Each SunRay requires ~30KByte/sec for normal office usage.





They never break, average life expectancy is 22 years. SunRay is a small plastic box, very similar to a VHS cassette. It is just another keyboard or mouse, an input device. Can not be hacked. You can have dozens of them in a drawer. Should you need another work station, just insert SunRay into the router/hub and you are done. Anyone could do that.

Hot desking is also supported. Insert your security card and you have logged in. Then withdraw the card and insert it into another SunRay and you are back immediately where you left.

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

If we speak about low end gear (as you do about diskless PC), you can find refurbished SunRay at 40 USD on Ebay. That is cheaper than a low end diskless PC. Never need upgrading too. A new one cost 200 USD. But they never break. Use them forever.

Here is an article about U.S Army switching to SunRay for their class rooms and saving lots of work and energy and money.
http://www.sun.com/customers/software/usaic.xml

There are Linux only solutions with SunRay. You dont have to use VMware and Windows XP. You can run everything as normal Linux users, creating normal Linux accounts, etc.

Reply Parent Score: 2

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

broken_symlink Member since:
2005-07-06


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.


Diskless pc's do not have to use "weak" cpus. I used to have a diskless setup at home for testing purposes, and each system had an athlon 64 running at 2.2ghz ea, with 1gb ram. Is that weak?


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. Worst case, you have to upgrade them all (very expensive), or worse, ditch all diskless PCs and buy new ones. With SunRay, you instead upgrade the server and at once all the SunRays have been upgraded. You can always use your SunRays, they never need to upgrade. Use them for 22 years, if you wish. They always handles the latest OS and newest software excellent. 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.


And why exactly aren't they? If performance starts to become an issue in a few years there is absolutely nothing preventing you from turning them into thin-clients with something like ltsp. So, you get the best of both worlds.


Diskless PCs also suck as much energy as a normal PC. Compare that to 4Watt SunRay. Say you have 1000 diskless PC each using 100 watt. That is 100,000Watt. With SunRay, that is 4000Watt.


I agree with you here, but if you use an atom based system for your diskless client there is no reason why you can't save power, probably not as much as a sun ray, but still anything is better than nothing.


You have no serious performance with diskless PC if you need to do say, a heavy compilation. With SunRay, you have as much power as the server has. A server will always be much much more powerful than a diskless PC or thin client. If you are alone on the server, then all it's powers is yours.


This is the one thing that is absolutely not true at all. Diskless pcs could wipe the floor with thin clients in this area. I used my athlon 64 diskless setup for nothing but compiling stuff. Tell me which setup you think would perform better, 50 sun rays, with a quad core server, or 50 diskless systems with pentium 3s all compiling stuff at once. The thing about using the diskless sysetms is that you can use a distributed compiler like distcc and compile on all 50 systems at once. You can also use stuff like openmosix to migrate processes between the diskless systems, and theoretically end up with unlimited resources for the task at hand.


The only thing you can not do with SunRay, is high bandwidth graphics. You can watch movies at 500x500 windows without lagg. But that is graphic intense, compared to ordinary office usage and software development. For all other uses than watching movies, SunRay does it excellent. Many SunRay servers dont have any graphic card. The server generates bitmaps in RAM and sends to each SunRay. Each SunRay requires ~30KByte/sec for normal office usage.


That is constant network traffic that diskless pc's don't require, because once you start a program from the server on a diskless pc, it stays in the diskless pc's ram and there is no more communication required with the server unless something needs to be written to disk. So, you save bandwidth.


They never break, average life expectancy is 22 years. SunRay is a small plastic box, very similar to a VHS cassette. It is just another keyboard or mouse, an input device. Can not be hacked. You can have dozens of them in a drawer. Should you need another work station, just insert SunRay into the router/hub and you are done. Anyone could do that.


I see no reason why the same can't be done with a diskless pc. One breaks, just plug a new one. Sure, not anyone can do it because you need to edit a file or two. They also may take up more space than a sun ray, but honestly I would rather deal with those issues than trade the flexibility a diskless pc gives you.


Hot desking is also supported. Insert your security card and you have logged in. Then withdraw the card and insert it into another SunRay and you are back immediately where you left.


I'm sure something similar could be done with linux and a diskless pc, maybe even using a fingerprint reader, which is something we wouldn't have to wait for sun to implement in the diskless world.


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


As far as I know you can't do this with a diskless system, but there are other options available, like ssh.


If we speak about low end gear (as you do about diskless PC), you can find refurbished SunRay at 40 USD on Ebay. That is cheaper than a low end diskless PC. Never need upgrading too. A new one cost 200 USD. But they never break. Use them forever.


I got all my diskless pc's for free. People where throwing them away. You still need to buy a keyboard, monitor, and mouse for both solutions though. If I were going to buy new diskless clients today, I would probably get something like this, http://www.newegg.com/Product/Product.aspx?Item=N82E16813121359

That is $79 for a 1.6ghz dual-core cpu that uses 8w of power. I found a case with powersupply and 2gb of ram on newegg for another $70. That brings the total price for a brandnew mini-itx diskless system to $150. Another thing that should be noted is that that atom motherboard comes with gigabit ethernet, and according to this http://tinyurl.com/3vv9vv the sun ray2 is $349 brandnew from sun with only 10/100 nic, which is weak.


There are Linux only solutions with SunRay. You dont have to use VMware and Windows XP. You can run everything as normal Linux users, creating normal Linux accounts, etc.


You can do the same with diskless pcs, but they are not linux only. There is nothing keeping you from using netbsd, freebsd, or anything else that can netboot. Heck, it might even be possible to netboot osx, if you had a little know how. You can also run windows directly on the system using xen or something if the diskless system has a cpu that supports virtualization extensions.

I still don't see whats so great about thin clients when diskless systems offer so much more. Especially when you consider that they are proprietary and closed source. Tell me how a sun ray can last 20 years if sun decides to stop supporting it in 5 years. What do you do with all those thin clients then? How do you replace one if it breaks and sun doesn't sell them? They can't be turned into full blown pcs either if the need arises.

Edited 2009-03-04 21:40 UTC

Reply Parent Score: 2