2008.4.24 16.37.44 hudson.Proc$LocalProc join
WARNING: Process leaked file descriptors. See http://hudson.gotdns.com/wiki/
display/JENKINS/Spawning+processes+from+build for more information
java.lang.Exception
at hudson.Proc$LocalProc.join(Proc.java:127)
at hudson.scm.CVSSCM.run(CVSSCM.java:805)
at hudson.scm.CVSSCM.update(CVSSCM.java:423)
at hudson.scm.CVSSCM.pollChanges(CVSSCM.java:230)
at hudson.model.AbstractProject.pollSCMChanges(AbstractProject.java:597)
at hudson.triggers.SCMTrigger$Runner.runPolling(SCMTrigger.java:261)
at hudson.triggers.SCMTrigger$Runner.run(SCMTrigger.java:293)
at java.util.concurrent.Executors$RunnableAdapter.call
(Executors.java:417)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:269)
at java.util.concurrent.FutureTask.run(FutureTask.java:123)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask
(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run
(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)

After that process runing tomcat with hudson is cloned:

root@hudson:~ # ps -ef | grep java
root 15656 563 0 15:36:24 pts/7 1:48 /usr/jdk/jdk1.5.0_07/bin/
java -Dcatalina.base=/opt/java/hudson/apache-tomcat-5.
root 16226 15656 0 16:36:04 pts/7 0:00 /usr/jdk/jdk1.5.0_07/bin/
java -Dcatalina.base=/opt/java/hudson/apache-tomcat-5.
root 16375 15656 0 17:16:04 pts/7 0:00 /usr/jdk/jdk1.5.0_07/bin/
java -Dcatalina.base=/opt/java/hudson/apache-tomcat-5.

and after or more such leaks we cannot build anymore because:
[workspace] $ /sbin/sh -xe /opt/java/hudson/apache-tomcat-5.5.17/temp/
hudson50720.sh
FATAL: command execution failed
java.io.IOException: Not enough space
at java.lang.UNIXProcess.forkAndExec(Native Method)
at java.lang.UNIXProcess.<init>(UNIXProcess.java:53)
at java.lang.ProcessImpl.start(ProcessImpl.java:65)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:451)
at hudson.Proc$LocalProc.<init>(Proc.java:83)
at hudson.Launcher$LocalLauncher.createLocalProc(Launcher.java:292)
at hudson.Launcher$LocalLauncher.launch(Launcher.java:283)
at hudson.Launcher.launch(Launcher.java:121)
at hudson.Launcher.launch(Launcher.java:73)
at hudson.tasks.CommandInterpreter.perform(CommandInterpreter.java:60)
at hudson.tasks.CommandInterpreter.perform(CommandInterpreter.java:34)
at hudson.model.Build$RunnerImpl.build(Build.java:147)
at hudson.model.Build$RunnerImpl.doRun(Build.java:123)
at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:184)
at hudson.model.Run.run(Run.java:659)
at hudson.model.Build.run(Build.java:101)
at hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:71)

adding more swapspace adds a few hours. but this happens everyday.