I changed the core file dump path to sdcard, but error happened

Question

I do android development, and i open coredump and set core file dump path to sdcard in file init.rc, use below code:

setrlimit 4 -1 -1
write /proc/sys/kernel/core_pattern /sdcard/core.%e.%p
write /proc/sys/fs/suid_dumpable 1

it do generates core file , but its size is 0. As below:

 mtk        0 2013-07-12 14:48 core.b2g.127

and i modify the code as below :

setrlimit 4 -1 -1
chmod 0777 /data/core/
write /proc/sys/kernel/core_pattern /data/core/core.%e.%p
write /proc/sys/fs/suid_dumpable 1

it can work well,as below:

mtk        280055 2013-07-12 15:28 core.b2g.127

why i store core file to sdcard occur the issue?

Answer 1

check the sd card mount correct or not and check also its properties about the sdcard (755), we may mount the sdcard to /mnt or something else when system boot up. method as below, in init.rc file , before below setting

setrlimit 4 -1 -1
write /proc/sys/kernel/core_pattern /mnt/sdcard/core.%e.%p
write /proc/sys/fs/suid_dumpable 1

do below setting:

mount /dev/mmcblk0p1 /mnt/sdcard
chmod 755 /mnt/sdcard.

i think it should be OK.