UNIX for Dummies Questions & Answers

I've got a core dump in my weblogic home directory, which i have tried to debug by initiating savecore from /etc/init.d/savecore start
but savecore failed to create the two files, that is vmcore.n and vmunix.n.
savecore is enable on my server to save vmcore and vmunix in /var/crash/hostname

1) how do I run adb command (debugger) without the vmcore.n or vmunix.n?

2) how do get my server to create the two files without rebooting?

3) could you debug a core file without creating or using vmcore and vmunix files?

You should be able to do this with just the kernel and the corefile. According to the man adb page, you should be able to use, adb <kernel> <corefile>...

Whoa! I think you may have your core files mixed up.

One type of corefiles is a file called "core" that appears in various directories around your system. When a process aborts as the result of a default action of certain uncaught signals, it tries to write a file called "core" in the current directory. This type of core file is just the stack and data segments of the process that aborted.

A second type of corefile occurs when the kernel detects a massive problem. The kernel will call an internal routine called "panic". panic will try to dump all of main memory to the swap area. Then is will halt or reboot depending on your config. When the box finally does boot, savecore will copy the corefile into the file system.

adb can be used on both types of corefiles. Type two is the type that needs a copy on vmunix. Type one on ethe other hand will need the executable that was running to cause the core file.

thanks for your reply, it being a great help in
differentiating the two types of core files

but when I initiated adb core it displays:

core file = core -- program ``dtfile'' on platform SUNW,Sun-Blade-100
SIGSEGV: Segmentation Fault

and nothing else.

is this all adb core is ment to display? or have
I got the syntax wrong? if this is the case could you please let me know what the right syntax is,
I have read the man page but this hasn't help.

adb is an interactive program. You type stuff in and it types stuff back. There is a limit to what it can do with only the core file. I wasn't kidding when I said it also needed the executable.

But even with the executable, you will need extensive knowledge to do much beyond displaying what you have displayed. Tutorials on adb have been mentioned before in this forum. Search for them.