Runtime error during CCSD(T) geo optimization

I get the following runtime error while doing a geometry optimization with CCSD(T)/aug-ccpwCVTZ, immediately after the DF-CCSDL iterations, while trying to compute 3-index intermediates:

RuntimeError:
Fatal Error: PSIO Error
Error occurred in file: /scratch/psilocaluser/conda-builds/psi4_1506620042465/work/psi4/src/psi4/libpsio/error.cc on line: 129
The most recent 5 function calls were:

psi::psio_error(unsigned long, unsigned long)
psi::PSIO::rw(unsigned long, char*, psi::psio_address, unsigned long, int)
psi::PSIO::write_entry(unsigned long, char const*, char*, unsigned long)
psi::dfoccwave::Tensor2d::write(std::shared_ptrpsi::PSIO, unsigned long)

What is the reason?

Did you investigate disk fullness (df -mh)? That’d be my first suspect. If perchance you haven’t set :envvar:PSI_SCRATCH and have been relying on scratch defaulting to /tmp/, the time to remedy that is now (http://psicode.org/psi4manual/master/external.html#scratch-files-and-elementary-restart).

I am using the DF algorithm for the mentioned calculation on a machine with 60 GB RAM, the DF-CCSD iterations are performed in a reasonable amount of time; however, the run is stuck forever at the DF-CCSD(T) step while computing the (T) correction. Is there a way to make it faster?