Allocate a very large(>900GB) array with -qopenmp result in segmentation fault

Wow, I never there are print and execute_command_line intrinsic functions, many new things to learn.

Anyway, I finally get access to the node now. The job is submitted in Slurm. Here is the output from your script.
I compiled with:

ifort -qopenmp memtest_urbanjost.f90 -o memtest_urbanjost.exe

output is:

 Hello from process:            0
This file was compiled by Intel(R) Fortran Intel(R) 64 Compiler Classic for applications running on Intel(R) 64, Version 2021.5.0 Build 20211109_000000using the options -qopenmp -o memtest_urbanjost.exe
              total        used        free      shared  buff/cache   available
Mem:           2.0T         23G        1.9T        9.9G         10G        1.9T
Swap:            0B          0B          0B
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 8205077
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 4096
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) unlimited
cpu time               (seconds, -t) unlimited
max user processes              (-u) 4096
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
Trying to allocate   10GB --> OK
Trying to allocate   20GB --> OK
Trying to allocate   30GB --> OK
Trying to allocate   40GB --> OK
Trying to allocate   50GB --> OK
Trying to allocate   60GB --> OK
Trying to allocate   70GB --> OK
Trying to allocate   80GB --> OK
Trying to allocate   90GB --> OK
Trying to allocate  100GB --> OK
Trying to allocate  110GB --> OK
Trying to allocate  120GB --> OK
Trying to allocate  130GB --> OK
Trying to allocate  140GB --> OK
Trying to allocate  150GB --> OK
Trying to allocate  160GB --> OK
Trying to allocate  170GB --> OK
Trying to allocate  180GB --> OK
Trying to allocate  190GB --> OK
Trying to allocate  200GB --> OK
Trying to allocate  210GB --> OK
Trying to allocate  220GB --> OK
Trying to allocate  230GB --> OK
Trying to allocate  240GB --> OK
Trying to allocate  250GB --> OK
Trying to allocate  260GB --> OK
Trying to allocate  270GB --> OK
Trying to allocate  280GB --> OK
Trying to allocate  290GB --> OK
Trying to allocate  300GB --> OK
Trying to allocate  310GB --> OK
Trying to allocate  320GB --> OK
Trying to allocate  330GB --> OK
Trying to allocate  340GB --> OK
Trying to allocate  350GB --> OK
Trying to allocate  360GB --> OK
Trying to allocate  370GB --> OK
Trying to allocate  380GB --> OK
Trying to allocate  390GB --> OK
Trying to allocate  400GB --> OK
Trying to allocate  410GB --> OK
Trying to allocate  420GB --> OK
Trying to allocate  430GB --> OK
Trying to allocate  440GB --> OK
Trying to allocate  450GB --> OK
Trying to allocate  460GB --> OK
Trying to allocate  470GB --> OK
Trying to allocate  480GB --> OK
Trying to allocate  490GB --> OK
Trying to allocate  500GB --> OK
Trying to allocate  510GB --> OK
Trying to allocate  520GB --> OK
Trying to allocate  530GB --> OK
Trying to allocate  540GB --> OK
Trying to allocate  550GB --> OK
Trying to allocate  560GB --> OK
Trying to allocate  570GB --> OK
Trying to allocate  580GB --> OK
Trying to allocate  590GB --> OK
Trying to allocate  600GB --> OK
Trying to allocate  610GB --> OK
Trying to allocate  620GB --> OK
Trying to allocate  630GB --> OK
Trying to allocate  640GB --> OK
Trying to allocate  650GB --> OK
Trying to allocate  660GB --> OK
Trying to allocate  670GB --> OK
Trying to allocate  680GB --> OK
Trying to allocate  690GB --> OK
Trying to allocate  700GB --> OK
Trying to allocate  710GB --> OK
Trying to allocate  720GB --> OK
Trying to allocate  730GB --> OK
Trying to allocate  740GB --> OK
Trying to allocate  750GB --> OK
Trying to allocate  760GB --> OK
Trying to allocate  770GB --> OK
Trying to allocate  780GB --> OK
Trying to allocate  790GB --> OK
Trying to allocate  800GB --> OK
Trying to allocate  810GB --> OK
Trying to allocate  820GB --> OK
Trying to allocate  830GB --> OK
Trying to allocate  840GB --> OK
Trying to allocate  850GB --> OK
Trying to allocate  860GB --> OK
Trying to allocate  870GB --> OK
Trying to allocate  880GB --> OK
Trying to allocate  890GB --> OK
Trying to allocate  900GB --> OK
Trying to allocate  910GB --> OK
Trying to allocate  920GB --> OK
Trying to allocate  930GB --> OK
Trying to allocate  940GB --> OK
Trying to allocate  950GB --> OK
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image              PC                Routine            Line        Source             
memtest_urbanjost  000000000040B09A  Unknown               Unknown  Unknown
libpthread-2.17.s  00002B2F2952D630  Unknown               Unknown  Unknown
libiomp5.so        00002B2F2924FFEE  Unknown               Unknown  Unknown
libiomp5.so        00002B2F2924D7C6  Unknown               Unknown  Unknown
libiomp5.so        00002B2F2924D2F8  Unknown               Unknown  Unknown
libiomp5.so        00002B2F29247993  Unknown               Unknown  Unknown
libiomp5.so        00002B2F2924834D  Unknown               Unknown  Unknown
memtest_urbanjost  0000000000423A11  Unknown               Unknown  Unknown
memtest_urbanjost  00000000004043A6  Unknown               Unknown  Unknown
memtest_urbanjost  0000000000403FA2  Unknown               Unknown  Unknown
libc-2.17.so       00002B2F2975C555  __libc_start_main     Unknown  Unknown
memtest_urbanjost  0000000000403EA9  Unknown               Unknown  Unknown
Trying to allocate  960GB

This is weird: the loop that allocates 950GB array is successful, then the next causes segfault. I don’t think this caused by

i = i + 10
n = i * 1024_8**3 / 8

then something must happen between the loops.