On Fri, 2009-10-30 at 15:38 -0700, Suvayu Ali wrote:
Hi Patrick,
Patrick O'Callaghan wrote:
On Fri, 2009-10-30 at 08:02 -0700, Suvayu Ali wrote:
I often find nohup very unreliable. I have had jobs fail submitted with nohup. I was thinking of switching to using screen. Maybe you could give that a try?
Screen is not an option if you want to set up a long-running job and log out. In what way has nohup failed on you? It's one of the oldest commands in the Shell toolbox and I've never had a problem with it.
Note that it's often a good idea to run it thus:
nohup command > OUTPUT 2>&1 &
Whenever I have used nohup I have used it exactly the way you have mentioned. And many times I later found out my job had failed when I had logged out. Since then I have stopped using nohup and wanted to look into screen. Until I do that I just don't log out any more unless I am sure my job has finished. Maybe the unreliability I have experienced is due to the versions of nohup I use (what ever comes as default with Scientific Linux 4, thats way too old).
I guess commands under nohup can fail if they expect to send output to a physical terminal, which presumably screen handles better. I can't think what other reason could make them fail. Anything written to be used as a filter shouldn't have this problem, but of course it depends what you're doing.
poc