Setting up scheduled BOINC client updates with cron (Linux)

[D_A]

Ok, after a discussion with Dave I figured I?d better do a write up for those starting with Linux and who wanted to schedule BOINC to upload results more often than their WCG preferences would trigger, so here goes.

First a little background on the tools we?ll be using. Scheduled tasks in Linux are handled by a program called ?cron?. It?s surprisingly simple to use considering just how much it can do, but isn?t exactly intuitive for a native Windows user. Cron performs tasks for every user as required based on each user?s ?crontab? or cron table. That is what we are going to edit to get cron to do what we want and it has it?s own commands. The editing is done by default using a very powerful text editor called vi, but it has a very steep learning curve so the first thing we?ll do is change that for this session to something that?s not as powerful but easier to manage, ?nano?.

Open a terminal and enter

export EDITOR=nano

Until you log out and back in again your default editor is now nano instead of vi.

Next we open the crontab for editing

crontab -e

What will open will look something like this:


Most of the window is blank because there are no jobs there yet.
This is the crontab I use on this machine:


The line we?re particularly interested in is the first one.

55     10     *     *     *         /home/michael/BOINC/boinccmd --project www.worldcommunitygrid.org update >/dev/null 2>&1

This line tells cron that at the 55th minute of the 10th hour every day it should run the binary file ?boinccmd? with the parameters ?--project www.worldcommunitygrid.org update? and send any output (the stuff you?d see if you just executed the command in the terminal) to ?/dev/null 2>&1?. The last bit means it will send all output messages to /dev/null, so it will execute the command silently. The asterisks need to be there for each time scale you don?t set a value for.

I run it once a day to make sure I have returned all work before the WCG stats run. If you wanted to update every hour, every day, every month, at minute 0 you could edit that line to read

 0     *     *     *     *         /home/michael/BOINC/boinccmd --project www.worldcommunitygrid.org update >/dev/null 2>&1

or if you just wanted WCG to update every day just before the validation runs like I do you could change the ?10? to the hour before the stats run where you are. Remember it?s that hour plus the 55 minutes. If the stats run is at midnight your local time you could edit the line to read

 55     23     *     *     *         /home/michael/BOINC/boinccmd --project www.worldcommunitygrid.org update >/dev/null 2>&1

to update your machine at five minutes before midnight. All times are in 24 hour format.
If you have a repository install of BOINC the path to the command will be different.

 55     10     *     *     *         /usr/bin/boinccmd --project www.worldcommunitygrid.org update >/dev/null 2>&1

Getting that line into the editor might be as easy as copying and pasting with the mouse or you might have to type it in long hand. That depends on your machine setup and environment variables, and machines do vary.

Once you have that entered, press <Ctrl>+o (control key and the letter ?o?) to output the file (ie save it) and then just press <Enter>. To exit the editor press <Ctrl>+x and you will return to the terminal.

There are also graphical interfaces to do this if you really don?t like terminal editors, but this is the most consistent way to do it across all the various desktop environments.