You should have the two files hostcert.pem and hostkey.pem in your /etc/grid-security directory. The file hostcert.pem should have permissions allowing anyone to read the file; however, the file hostkey.pem must have permissions that prevent anyone except root from reading the file.

You should check this:

[root@dcache-node] # ls -l /etc/grid-security/host*
-rw-r--r--  1 root root 5132 Aug 20 13:15 /etc/grid-security/hostcert.pem
-r--------  1 root root  887 Aug 20 09:00 /etc/grid-security/hostkey.pem