core file generated by Medusa

[Venkatesan_5]

Hi,

I need your help in diagnosing a problem, a core file has been generated by medusa. If I give

# file core
the output is ..
core: core file from 'medusa_job6712' - received SIGSEGV

what does this mean and how to address it..

Thanks in advance.

Venkatesan

[Steven E. Protter]

Shalom,

The actual core file may be useful to the developer.

Take a quick look at it with strings command.

strings core | more

nice sounding command anyway.

SEP

[Steve Steel]

Hi


memory problem

increase maxssiz maxdsiz in kernel


Steve Steel

[Venkatesan_5]

Hi Steve,

Thanks for your idea, but I would like to know how do you say that these values has to be increased?, is there any special tools or methods available to diagnose?

regds

Venkatesan.

[Muthukumar_5]

SIGSEGV will come in application when there is resource crunch on memory. You can get the maxssiz, maxdsiz kernel parameter informations with SAM tool or kmtune -q -l will give that.

--
Muthu

[Sameer_Nirmal · Accepted solution]

Hi Venkatesan,

SIGSEGV is a signal 11 which means Segmentation Violation.

It may appear during a program compilation or while executing it. Common cause of this signal is lack of memory required by the program. The memory required is for program stack , data and text allocation.
These requirements could be know using "size" command.
The respective kernel parameters ( system limits) are maxtsize, maxssize, maxdsize or their 64bit eqivalent under 64 bit enviornment ( maxssize_64bit etc.)
Thus you can check those kernel parameters and tune them if required. It may not be problem with those paramters if the program is not written correctly to use memory space.

You can use a debugger like adb or WDB to debug the program by referncing the core file. The stack trace would be useful to track down the problem.

[Muthukumar_5]

Monitor the memory information as,

# vmstat
# top
# UNIX95=1 ps -ef -o pid,sz,vsz,comm
# sam -> performance monitor -> system properties -> memory tab

They will give the memory available and usage statistics.

--
Muthu

[Venkatesan_5]

Hi Sameer,

thank you for your explanation, may I know from where shall I get stack trace program or can I debug thru adb itself? if so how to do it, could you please explain me..


regds

Venkatesan.

[Steve Steel]

Hi

ftp://eh:spear9@hprc.external.hp.com/memory.htm

Gives all the tools you need


Steve Steel

[Muthukumar_5]

You can get stack trace as,

# what core
# gdb
gdb>bt

# adb
adb>$c

will give that.

--
Muthu