Re: crash: savecore - saves core dump every day?
Stefan Drexleri wrote: 2006/3/10, Nick Holland <[EMAIL PROTECTED]>: I'm not entirely sure I understand your question, the subject and the body of your message don't seem to be completely related. However, I think you may find the answers to your questions in man 8 crash Third paragraph (more or less, depending what one counts) tells what conditions cause the in-RAM image to be written to disk in the swap partition. If that happens, an attempt will be made to dump it to physical disk upon reboot. Will try to ask more clearly: How does savecore work in sense of detecting that condition to save core dump to swap space has been accomplished? Does it get message from kernel (which IPC technique?) or does it something like polling for special event (eg. newly created file)? Savecore is running after a reboot. It isn't getting a message from the now dead kernel through traditional techniques. After a kernel panic, it is generally not a great idea to write a normal file to a normal file system. As man 8 savecore indicates, it looks at the swap space to see if it looks like a valid core dump. If so, it dumps to disk. If you need more info on how it determines that, I'd suggest a read of the source code. If you really need that kind of information, you will probably have no problem with the source code (pretty small and contained, too -- about 16k in size). I suspect there is a question you are trying not to ask. What is prompting your questions? Are you having a problem? Trying to accomplish something? Nick.
Re: crash: savecore - saves core dump every day?
2006/3/10, Nick Holland <[EMAIL PROTECTED]>: > > I'm not entirely sure I understand your question, the subject and the > body of your message don't seem to be completely related. > > However, I think you may find the answers to your questions in >man 8 crash > > Third paragraph (more or less, depending what one counts) tells what > conditions cause the in-RAM image to be written to disk in the swap > partition. If that happens, an attempt will be made to dump it to > physical disk upon reboot. Will try to ask more clearly: How does savecore work in sense of detecting that condition to save core dump to swap space has been accomplished? Does it get message from kernel (which IPC technique?) or does it something like polling for special event (eg. newly created file)? regards
Re: crash: savecore - saves core dump every day?
Stefan Drexleri wrote: Hi, from the faq: "Upon reboot, savecore(8)will attempt to save the contents of the swap partition to a file in /var/crash" savecore would be called by /etc/rc. So which criterias must be fulfilled to make core dump upon reboot? Does savecore look for special file names at special places? Who makes the rule? I'm not entirely sure I understand your question, the subject and the body of your message don't seem to be completely related. However, I think you may find the answers to your questions in man 8 crash Third paragraph (more or less, depending what one counts) tells what conditions cause the in-RAM image to be written to disk in the swap partition. If that happens, an attempt will be made to dump it to physical disk upon reboot. Note that on a modern system, /var is very often not large enough to hold a core dump. If this is something you care about, you will need to deal with it accordingly. (aren't we all glad that attachments are stripped from misc@ postings now? "Hi, here's my 2G core dump. why did it happen?") Nick.
