Hi, I happened to meet with a similar issue like
https://bugs.centos.org/view.php?idp51
I found the root cause might be fixed by commit f13d4f979c518119bba5439dd2364d76d31dcd3f.
The commit in branch linux-2.6.32-y is 0bd9ac380a44611e953b1657d7f54075b2f77fb0
This issue is existed in centOS 6.6 also
any ideas
B.R.
Justin