topic Re: what is segmentation fault , and how to slove it ? in Operating System - Linux

what is segmentation fault , and how to slove it ?

tan chin tiau — Fri, 15 Jul 2011 09:48:38 GMT

Dear Linux / unix expert

my server is hp proliant G5 , OS is Linux Centos .

i got one error msg is " segmentation fault "

may i know why got this msg ? and how to solve it ?

Re: what is segmentation fault , and how to slove it ?

Naj — Fri, 15 Jul 2011 10:44:16 GMT

A segmentation fault or bus error is generally an attempt to access memory that the CPU.cannot physically address.It occurs when the hardware notifies a UNIX like operating system about a memory access violation.

Normally when we getting this error, we just reboot the server

Thanks

Re: what is segmentation fault , and how to slove it ?

Steven Schweda — Fri, 15 Jul 2011 14:29:24 GMT

may i know why got this msg ? and how to solve it ?

Is Google broken? A Web search for "segmentation fault" should get
you the whole Wikipedia article, not just the first part.

i got one error msg is " segmentation fault "

When you did _what_?

Normally when we getting this error, we just reboot the server

Some people try to find and fix the problem with the software.

Re: what is segmentation fault , and how to slove it ?

Hein van den Heuvel — Fri, 15 Jul 2011 14:33:19 GMT

[reply clash with Steven :-) ]

The prior reply (Naj) is a verbatim copy from http://en.wikipedia.org/wiki/Segmentation_fault without the reference.

If you want to address (sic) this issue, then

it behooves you to read that article or Google for more.
you need to describe the problem better in classic problem solving terms : what is being done when the error happens? did it ever work? what changed? When does it happen ('all the time', sometimes, when xyz is also being done, after the program runs for 6 days, ...)
any resources (memory, disk) being exhausted?

Just blindly rebooting the system is a rather blunt reaction, suggesting a clueless operator.

Reboot prohibits developing a full understanding and proper correction.

Reboot is a valid approach after (corrected) hardware issues, but a segmentation fault is 99.9% sure to be a software coding problem which will NOT be solved by a reboot, but just hidden for a while longer.

A more reasonable reaction might be to document the time, and take a quick system snapshot of sorts with 'vmstat', sar or similar, to get an impression of what was running at the time of the issue and then restart the process/job which failed. Does it work now, or fail again? Do other messages precede the segmentation fault?

Good luck!

Hein

Re: what is segmentation fault and how to solve it?

Dennis Handly — Sat, 16 Jul 2011 20:05:30 GMT

Do you have a core file so you can invoke a debugger?

Do you know which application is failing?

If the application doesn't have debug info, can you get a stack trace?

And even if you do all of this, is there anyone that supports that application so you can get it fixed?

Otherwise as Hein said, you may have to note it down, remove the core file and restart the application.

Re: what is segmentation fault and how to solve it?

Steven E. Protter — Tue, 19 Jul 2011 15:35:02 GMT

Shalom,

Most likely cause of this is an application trying to access memory not allocated to it.

The application must be identified (usually by core files or you revealing what command triggers the fault). Then its usually fixed by repairing the application or getting a patch from the application vendor.

SEP