Dear users, P.S. to the previous post:
1. To execute with multiple machines, outdir needs to be NFS-mounted in order to be visible from all processes. 2. In nowf case, wavefunction files exist, but 0KB in size. ---Sender--- Mr. Takahiro Chiba Undergraduate at Hokkaido University Expected graduation date: Mar. 2021 Expected to be a graduate student at HU from Apr. 2021 [email protected] ---送信者--- 北海道大学理学部化学科四年 千葉 卓紘 [email protected] ----- 2021年3月17日(水) 20:20 Takahiro Chiba <[email protected]>: > > Dear QE users, > > To lessen I/O with neb.x, what should I do? The 'outdir' grows really > fast. I want advice from experienced users or devs. > > Issue: > Although the image parallelism (neb.x -ni $NumOfNodes) is scaling well > with the number of nodes even with gigabit ethernet, massive I/O to > 'outdir' is observed. > 1. Regardless of the existence of the wfcdir option, wavefunctions > from each MPI processes (pwscf.wfc1, pwscf.wfc2, pwscf.wfc3, ... > pwscf.wfc$ProcPerNode) are written under 'outdir' except for the first > and the last image. Is this a bug? > 2. When the 'disk_io' option is set to 'nowf', the neb calculation > fails at the beginning of the second iteration because wavefunction > files cannot be opened for writing. To execute properly, 'low' or > above is necessary. I think this is expected by the devs, but warning > at the beginning would be better. > > These issues can be reproduced on: > a. QE 6.7, intel 19.5.281 (both MPI & compilers), CentOS 7, with LUSTRE > a. QE 6.5, intel 19.5.281 (both MPI & compilers), CentOS 7, with LUSTRE > b. QE 6.7, intel 19.5.281 (both MPI & compilers), CentOS 6, without LUSTRE > c. QE 6.5, intel 18.1.038 (both MPI & compilers), CentOS 6, without LUSTRE > ( a = Subsystem A in this page: > https://www.hucc.hokudai.ac.jp/en/supercomputer/sc-overview/ ) > According to the batch queue system on system A, it wrote 32.7GB/hour > when 4 x 40 processes each. The command is "mpiexec.hydra -n 160 neb.x > -ni 4 -i $INP >>$OUT". > > Again, my question is, what can I do to lessen I/O other than the > 'disk_io' option and 'wfcdir' option? > > ---Sender--- > Takahiro Chiba > Undergraduate at Hokkaido University > [email protected] > ----- _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
