(note: this workaround is from http://foldingforum.org/viewtopic.php?f=58&t=14782)

As you may or may not know version 6.29 of the Folding@Home SMP client for Linux doesn't work properly due to something wrong with the way the client is linked and doesn't like the Ubuntu libc. Fortunately it's only a minor fix to get it working again.

To those of you that are wondering why use the SMP client, I give you a single word: points. I was running 4 instances of F@H 6.02 in single thread mode and I'd get around 1000 points a day folding most of the day on a Core 2 Quad Q9400 at 3.8Ghz. Now that the SMP version is working my average is around 8000 points a day, more than what I used to get for a week! (my stats) The SMP version currently requires at least 4 cores and it should be a relatively fast machine running 64bit Linux, with plenty of RAM and a high uptime as the SMP cores have rather short deadlines. To get the most points you should also get a passkey and put it in below.

So without further ado, here's how to get SMP folding working.

1. Install F@H using Origami
(If you don't use Origami you can skip to step 3)
Origami is a nice little tool that makes the installation of F@H easier. It sets up the launch scripts and the user for you so that you don't have to worry about it. If you have origami already installed, please erase it to start over again by issuing this command:
Code:
sudo origami erase
Use this command to install Origami and tell it we want F@H to be folding for the Ubuntu team in SMP mode:
Code:
sudo origami install -t 45104 -u USERNAME -p amd64 -k PASSKEY -b big
Substitute in your user name and passkey and press enter. Note that the -p switch is set to amd64 as there is a bug in origami which means it only configures the client to SMP mode if it's set to amd64 (not smp).

2. Update the F@H client
After origami has done its job we need to update the client version. By default it comes with 6.02 which works with Ubuntu out of the box but doesn't support recent SMP cores, which means you won't get any work units. First we need to stop origami:
Code:
sudo origami stop
Then download the latest (6.29) F@H client and extract fah6 to your desktop (mpiexec is the same as the one origami downloaded so we don't need it). Then we need to move it to where origami stores the client and overwrite the original client:
Code:
sudo mv ~/Desktop/fah6 /var/lib/origami/foldingathome/CPU1/fah6
Also we should change the permissions and owner of the new client to how it was like for the old client, which is done by these 2 commands:
Code:
sudo chmod 711 /var/lib/origami/foldingathome/CPU1/fah6
sudo chown origami:nogroup /var/lib/origami/foldingathome/CPU1/fah6
3. Make 6.29 client work
As I said above there's a bug that stops 6.29 from working. Fortunately there's a simple fix to it by installing the package nscd:
Code:
sudo apt-get install nscd
Then, we need to change a value in its configuration file. First we gotta open the config file:
Code:
gksudo gedit /etc/nscd.conf
Then, find the line that says "enable-cache hosts no". Change that no to a yes, save, and restart nscd by doing:
Code:
sudo service nscd restar
Now you can start origami again by issuing
Code:
sudo origami start
And hopefully everything will work. The F@H log is at /var/lib/origami/foldingathome/CPU1/FAHlog.txt and you can open it to monitor progress/errors.

Caveats

  • NCSD has a potential security vulnerability if you turn host caching on (see link and link). If you're running a server and/or using Kerberos you should do a bit more reading to see if doing this workaround is a good idea.
  • The new SMP cores do have a low chance of failing mid way due to a bug in the core or things like that. If you see in the logs that F@H suddenly stopped half way through a WU and then went and fetched a new one don't panic, it might be perfectly normal.