We could do a better job documenting the "read-only" vs "read-write" nature of these hints... you cannot override the file system with the "romio_filesystem_type" hint, only confirm the file system is what you thought it was. you should be able to with the ROMIO_FSTYPE_FORCE environment variable. These symptoms suggest you requested quobyte support but ROMIO's configure could not find the development headers.... except ROMIO doesn't check for any development headers. Can you share with me the first few lines of ROMIO's config.log? From your build directory, that would be ` head mpich/src/mpi/romio/config.log` (the whole config.log is too much... for now) ==rob ________________________________________ From: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] via discuss <[email protected]> Sent: Wednesday, June 11, 2025 10:25 To: [email protected] Cc: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] Subject: Re: [mpich-discuss] [EXTERNAL] [BULK] How to make/run romio tests? An addendum, it's possible my "bugfix" as detailed in https: //github. com/pmodels/mpich/issues/7452 might not be enough. I have a code that uses `MPI_Info_set` to, well, set infos and I can't seem to affect the fs type. First I set:  ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd An addendum, it's possible my "bugfix" as detailed in https://urldefense.us/v3/__https://github.com/pmodels/mpich/issues/7452__;!!... <https://urldefense.us/v3/__https://github.com/pmodels/mpich/issues/7452__;!!G_uCfscf7eWS!aqjYcygbr3I8ZbKEHR9uOfQmiIa7WR2lVajdfRCYksA9leIz6X8t0pUZ9m8BzT8XyErKAf5BrG_M2fsmgucN-O7Wg10$> might not be enough. I have a code that uses `MPI_Info_set` to, well, set infos and I can't seem to affect the fs type. First I set: export ROMIO_PRINT_HINTS=1 and then in my code I added: call MPI_INFO_SET(info,"romio_filesystem_type","QUOBYTEFS:", status) but, well: key = romio_filesystem_type value = UFS: Generic ROMIO driver for all UNIX-like file systems I also tried it in lowercase as well. No joy. I've also tried: export ROMIO_FSTYPE_FORCE="QUOBYTEFS:" and: export ROMIO_FSTYPE_FORCE="quobytefs:" but in each case, it's still UFS. I do know my Infos are being seen by MPICH because if I toggled: call MPI_INFO_SET(info,"romio_cb_write","enable", status) from enable to disable, the ROMIO_PRINT_HINTS show the change. Matt [signature_3627681122]<https://urldefense.us/v3/__http://www.ssaihq.com/__;!!G_uCfscf7eWS!aqjYcygbr3I8ZbKEHR9uOfQmiIa7WR2lVajdfRCYksA9leIz6X8t0pUZ9m8BzT8XyErKAf5BrG_M2fsmgucNFDu3aGQ$> Matt Thompson Lead Scientific Software Engineer/Supervisor Global Modeling and Assimilation Office Science Systems and Applications, Inc. Code 610.1, 8800 Greenbelt Rd, Greenbelt, MD 20771 o: 301-614-6712 [email protected]<mailto:[email protected]> From: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] via discuss <[email protected]> Date: Wednesday, June 11, 2025 at 9:37 AM To: [email protected] <[email protected]> Cc: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] <[email protected]> Subject: [EXTERNAL] [BULK] [mpich-discuss] How to make/run romio tests? All, I'm trying to do some tests on a Quobyte system and we've seen confusing file write timings with Intel MPI and Open MPI. So, a bit of googling seeing if some MPI stack has a mention of Quobyte turns up: https: //www. quobyte. com/blog/quobyte-mpi-io-support-with-kernel-bypass-now-available/ ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd All, I'm trying to do some tests on a Quobyte system and we've seen confusing file write timings with Intel MPI and Open MPI. So, a bit of googling seeing if some MPI stack has a mention of Quobyte turns up: https://urldefense.us/v3/__https://www.quobyte.com/blog/quobyte-mpi-io-suppo... <https://urldefense.us/v3/__https://www.quobyte.com/blog/quobyte-mpi-io-support-with-kernel-bypass-now-available/__;!!G_uCfscf7eWS!foSdMay5QSiTxv1dePpWE5p5EOqkyr5hGLVXtgYBy6sY2_p9bErxn31S50_D4xpBCr1CIJCYqJV6YIlpDH99oVGEJLU$> and, yep, quobyte seems to be in MPICH! I grabbed MPICH 4.3.0 and built it (with one bug fix[1]) and well, it seems to run Hello World. So, following that Quobyte page, I get to Step 10 and tried the romio tests and...I am apparently dumb. I went to my build/src/mpi/romio/test directory and I see 'runtests' there, but:

./runtests make: *** No rule to make target 'default'. Stop.

I also tried with -fname and:

./runtests -fname=quobyte:test_mpi_file ./runtests: line 90: [quobyte:test_mpi_file: command not found make: *** No rule to make target 'default'. Stop.

./runtests -fname=quobyte:/home/mathomp4/MPI/src/mpich-4.3.0/build-ifort-2021.13/src/mpi/romio/test/test_mpi_file ./runtests: line 90: [quobyte:/home/mathomp4/MPI/src/mpich-4.3.0/build-ifort-2021.13/src/mpi/romio/test/test_mpi_file: No such file or directory make: *** No rule to make target 'default'. Stop.

Yeah. I'm stumped. I'm guessing I've missed some simple step along the way. NOTE: I have no idea even how to use romio really, but I was hoping the tests could, well, help me figure that out. Thanks for any help, Matt [1] See https://urldefense.us/v3/__https://github.com/pmodels/mpich/issues/7452__;!!... <https://urldefense.us/v3/__https://github.com/pmodels/mpich/issues/7452__;!!G_uCfscf7eWS!foSdMay5QSiTxv1dePpWE5p5EOqkyr5hGLVXtgYBy6sY2_p9bErxn31S50_D4xpBCr1CIJCYqJV6YIlpDH99XaSWwF0$> [signature_3314915376]<https://urldefense.us/v3/__http://www.ssaihq.com/__;!!G_uCfscf7eWS!foSdMay5QSiTxv1dePpWE5p5EOqkyr5hGLVXtgYBy6sY2_p9bErxn31S50_D4xpBCr1CIJCYqJV6YIlpDH99MYB1cYk$> Matt Thompson Lead Scientific Software Engineer/Supervisor Global Modeling and Assimilation Office Science Systems and Applications, Inc. Code 610.1, 8800 Greenbelt Rd, Greenbelt, MD 20771 o: 301-614-6712 [email protected]<mailto:[email protected]>