Linux - SoftwareThis forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Introduction to Linux - A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.
For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.
Click Here to receive this Complete Guide absolutely free.
Hi everyone. I have a HUGE problem, that I can't seem to get passed, and someone suggested that my problem might be with my RH Linux. I really need some help on this - newbie at a complete loss.
My app was running Apache & Tomcat, on a RH 7.3 box. We had a brownout yesterday, and now I cannot start Tomcat as any other user except for root. I have tried reinstalling tomcat & reinstalling my JDK... but nothing seems to be working. The java errors I am getting are:
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Caused by: java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start(Native Method)
... 5 more
Exception in thread "main" java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start(Native Method)
It was suggested that the problem is with the Java Virutal Machine and that I should change OS's. Obviously this is not an option - I need to get this working on my box.
So my question is - can I troubleshoot or reinstall the Java Virtual Machine? If so, does anyone have any clue about how to do this? I find it hard to believe that I am going to have to rebuild/restore my entire box (again) for this...
If you re-installed the JDK, that should have given you a fresh copy of the JVM......unless there were two copies of Java installed. Run which java or java -version. If those don't jibe with where (and what version) of the JDK you installed, then you'll have to point to the new JDK. Also, can you run any other Java dependant software?
everything looks fine when I run which java and java-version... There should only be that one java installation on my machine.
I can run java programs directly under any user. Its just starting Tomcat that I can only do as root. I thought it was a Tomcat problem, but I reinstalled that - and according to the Tomcat user groups the problem is not with Tomcat...
I am at a complete loss, and I am desperately trying to avoid having to reinstall Linux, and restore my entire machine... I find it hard to believe that there is no solution for this...
Dang. I was hoping that it would be something easy. To me this looks like a permissions issue. If Java works fine with everything except Tomcat, there can't be anything wrong with the JVM.
OK, here is a weird thought. When you re-installed the JDK, was it the same version as you had previously? My personal experience is that 1.4.2 is a little flaky and if you do a search on Java here, you'll see that loads of people have a problem finding a Java that is compatible with their machine. Usually, it seems to boil down to what version of gcc was used to compile Java.
If you did change Java versions, I'd go back to the old one. As an alternative, you could get Blackdown Java and try that. For many people, this works when an equivalent version of Sun Java doesn't. As far as I can tell, Blackdown isn't changing anything except how they compile Java, so compatibility doesn't seem to be an issue.
Yes, I reinstalled the same version of the JDK. Should I try changing to a difference version, perhaps an earlier one?
What makes this whole scenario strange is that everything was working absolutely fine - then all of a sudden this happens. When I try to start Tomcat as a non-root user I get the java errors, Tomcat starts - but the threads only stay alive for approximatey 30 seconds, then Tomcat shuts down.
Well the problem has been solved (at least I think, and hopefully its permanent). The problem turned out to be that when I was following the "Securing and Optimizing RH Linux" guide, I made some settings in my /etc/security/limits.conf. The settings I made allowed:
max memory size (kbytes, -m) 5000
max user processes (-u) 20
Apparently this was not even enough for Tomcat to run. As someone on the Tomcat list suggested I changed this to allow:
max memory size (kbytes, -m) unlimited
max user processes (-u) 256
And now I can start Tomcat as a non-root user no problem. I am not sure why the original settings worked fine until a few days ago, and that will require some research. But in the meantime this appears to have solved the problem.