db2_install do not have write permission on the directory or file

This is the error I encountered (I ran the db2_install and everything else as root,): DBI1288E The execution of the program /home/DB_SERVER/ibm/db2/v10.5 failed. This program failed because you do not have write permission on the directory or file . I tried to change the access permission of the path: chmod -R a+rw /home/DB_SERVER/ibm/db2/v10.5 And then I could create a new file in that folder: vi test Result of ll in that directory: total 1 -rw-rw-rw- 1 root root 12 Nov 23 00:24 test But when I ran the db2_install again, it failed for the same reason. PS: I tried to change permission of the setup file too chmod -R a+rwx db2Setup/ Result of ll total 72 drwxrwxrwx 6 root root 4096 Nov 23 00:10 db2 -rwxrwxrwx 1 root root 5349 Nov 23 00:10 db2ckupgrade -rwxrwxrwx 1 root root 5302 Nov 23 00:10 db2_deinstall -rwxrwxrwx 1 root root 5172 Nov 23 00:10 db2_install -rwxrwxrwx 1 root root 5136 Nov 23 00:10 db2ls -rwxrwxrwx 1 root root 5154 Nov 23 00:10 db2prereqcheck -rwxrwxrwx 1 root root 5154 Nov 23 00:10 db2setup drwxrwxrwx 10 root root 4096 Nov 23 00:10 ibm_im -rwxrwxrwx 1 root root 5190 Nov 23 00:10 installFixPack drwxrwxrwx 4 root root 4096 Nov 23 00:10 nlpack -rw-r--r-- 1 root root 8 Nov 23 01:00 test So I have no idea what's wrong? How to fix this?