I got a problem running my FORTRAN program in high performance computer cluster. It runs well in my PC but I want to have mass production of data with different initial conditions so I put it in a cluster node with eight cores, simulate eight sets of data. The program can run without problem in home directory but since I need extra memory space a scratch hard disk is added and I run the programs in this disk. After a while the program stopped and there is an error message: PGFIO/stdio: Input/output error PGFIO-F-/formatted write/unit=6/error code returned by host stdio - 5. File name = stdout formatted, sequential access record = 181 In source file TipNew8.f90, at line number 2018 FORTRAN STOP I have run it several times, similar error occurs but the error occurs at different lines. Also it stopped at different time steps each time I run it. This kind of error seems quite random since it occurs at different steps and different lines. Every time it occurs at lines with "write" or "print" function. It runs without problem when I run it in my PC using Microsoft Visual Studio with PGI compiler. Does anyone have ideas what's wrong with the program?