<div dir="ltr"><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d">Hi Wei-Keng,</div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d">I think that I've found the problem. In the model I am writing a number of scalar variables to the file as well as the decomposed variables.</div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d">for the scalar variables I use a code structure like:</div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">ncmpi_begin_indep_data(fh);</span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">ncmpi_put_vars_int(fh, varid, start, count, stride, data);</span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">ncmpi_end_indep_data(fh);</span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none"><br></span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">In my pioperf test code I didn't write any scalars - this morning I added one and the write performance for the decomposed variables got very very <br></span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">bad. What can I do about it?</span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none"><br></span></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:#38761d"><span style="color:rgb(29,28,29);font-family:Slack-Lato,Slack-Fractions,appleLogo,sans-serif;font-size:15px;font-style:normal;font-variant-ligatures:common-ligatures;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:left;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;display:inline;float:none">Jim<br></span></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 1:58 PM Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu">wkliao@northwestern.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
I believe the inconsistent values of cb_nodes is the culprit.
<div>I also noticed that striping_unit is different, 16 MB vs 1 MB.</div>
<div>My guess is the mechanism of setting cb_nodes in ROMIO needs a fix</div>
<div>when Lustre PFL is used. At the moment, I suggest not to use it.</div>
<div><br>
</div>
<div>
<div>Wei-keng </div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 2:43 PM, Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
Here is the info for the standalone pioperf program:</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH MPIIO environment settings
===============================<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_HINTS_DISPLAY
= 1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_HINTS
= NULL<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_ABORT_ON_RW_ERROR
= disable<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_CB_ALIGN
= 2<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_DVS_MAXNODES
= -1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_AGGREGATOR_PLACEMENT_DISPLAY
= 0<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_AGGREGATOR_PLACEMENT_STRIDE
= -1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_MAX_NUM_IRECV
= 50<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_MAX_NUM_ISEND
= 50<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_MAX_SIZE_ISEND
= 10485760<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_OFI_STARTUP_CONNECT
= disable<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_OFI_STARTUP_NODES_AGGREGATOR
= 2<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH MPIIO statistics environment
settings ====================<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_STATS
= 0<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_TIMERS
= 0<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPICH_MPIIO_WRITE_EXIT_BARRIER
= 1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: (t_initf) Read in prof_inparm namelist
from: <a href="https://urldefense.com/v3/__http://pioperf.nl__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJ07uO4BY$" target="_blank">
pioperf.nl</a><br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: Testing decomp: /glade/derecho/scratch/jedwards/piodecomps/32768/dof001.dat<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: iotype= 1 of
1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: PE 0: MPIIO hints for
<a href="https://urldefense.com/v3/__http://pioperf.2-0256-1.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJ2eymcFw$" target="_blank">
pioperf.2-0256-1.nc</a>:<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_pfr
= disable<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_fr_types
= aar<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: cb_align
= 2<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: cb_buffer_size
= 16777216<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_fr_alignment
= 1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_ds_threshold
= 0<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_alltoall
= automatic<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_read
= automatic<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_cb_write
= automatic<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_no_indep_rw
= false<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_ds_write
= automatic<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: ind_wr_buffer_size
= 524288<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_ds_read
= disable<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: ind_rd_buffer_size
= 4194304<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: direct_io
= false<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: striping_factor
= 24<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: striping_unit
= 16777216<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_lustre_start_iodevice
= -1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: aggregator_placement_stride
= -1<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: abort_on_rw_error
= disable<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: cb_config_list
= *:*<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: cb_nodes
= 24<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: cray_fileoff_based_aggr
= false<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: romio_filesystem_type
= CRAY ADIO:<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: RESULT: write SUBSET
1 256 64 12202.4897587597 24.8799532720<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: complete<br>
<a href="https://urldefense.com/v3/__http://dec1281.hsn.de.hpc.ucar.edu__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJlP5TXiA$" target="_blank">dec1281.hsn.de.hpc.ucar.edu</a> 0: calling mpi finalize<br>
</div>
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<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
And here it is for cesm:</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
PE 0: MPICH_MPIIO_HINTS_DISPLAY = 1<br>
PE 0: MPICH_MPIIO_HINTS = *:cb_nodes=24:striping_factor=24<br>
PE 0: MPICH_MPIIO_ABORT_ON_RW_ERROR = disable<br>
PE 0: MPICH_MPIIO_CB_ALIGN = 2<br>
PE 0: MPICH_MPIIO_DVS_MAXNODES = -1<br>
PE 0: MPICH_MPIIO_AGGREGATOR_PLACEMENT_DISPLAY = 0<br>
PE 0: MPICH_MPIIO_AGGREGATOR_PLACEMENT_STRIDE = -1<br>
PE 0: MPICH_MPIIO_MAX_NUM_IRECV = 50<br>
PE 0: MPICH_MPIIO_MAX_NUM_ISEND = 50<br>
PE 0: MPICH_MPIIO_MAX_SIZE_ISEND = 10485760<br>
PE 0: MPICH_MPIIO_OFI_STARTUP_CONNECT = disable<br>
PE 0: MPICH_MPIIO_OFI_STARTUP_NODES_AGGREGATOR = 2<br>
PE 0: MPICH_MPIIO_STATS = 0<br>
PE 0: MPICH_MPIIO_TIMERS = 0<br>
PE 0: MPICH_MPIIO_WRITE_EXIT_BARRIER = 1<br>
</div>
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<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
PE 0: MPIIO hints for <a href="https://urldefense.com/v3/__http://SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-00000.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!V4W0Yzn6BgsuwZ345_sC5f1F_sJy9ohr09OG6TCLvrYfI-ISwBySN82UBXJrDHTzWeT8o3jBGxifC8qJ4dcMF8Q$" target="_blank">
SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-00000.nc</a>:
<br>
romio_cb_pfr = disable <br>
romio_cb_fr_types = aar <br>
cb_align = 2 <br>
cb_buffer_size = 16777216
<br>
romio_cb_fr_alignment = 1 <br>
romio_cb_ds_threshold = 0 <br>
romio_cb_alltoall = automatic <br>
romio_cb_read = automatic <br>
romio_cb_write = automatic <br>
romio_no_indep_rw = false <br>
romio_ds_write = automatic <br>
ind_wr_buffer_size = 524288
<br>
romio_ds_read = disable <br>
ind_rd_buffer_size = 4194304 <br>
direct_io = false <br>
striping_factor = 24
<br>
striping_unit = 1048576 <br>
romio_lustre_start_iodevice = -1 <br>
aggregator_placement_stride = -1 <br>
abort_on_rw_error = disable <br>
cb_config_list = *:* <br>
cb_nodes = 1 <br>
cray_fileoff_based_aggr = false <br>
romio_filesystem_type = CRAY ADIO: <br>
</div>
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<br>
</div>
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<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
I'm trying to understand why cesm has cb_nodes=1 even though the striping_factor=24 and I explicitly set a hint for cb_nodes=24.<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 1:28 PM Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu" target="_blank">wkliao@northwestern.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>Hi, Jim
<div><br>
</div>
<div>Could you print all the MPI-IO hints for using the Lustre progressive file layout?</div>
<div>That may reveal some information.</div>
<div><br>
<div>Wei-keng </div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 1:45 PM, Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu" target="_blank">wkliao@northwestern.edu</a>> wrote:</div>
<br>
<div>
<div>Looks like the cesm file is using "Lustre progressive file layout", which is
<div>a new striping strategy. My guess is it is used center-widely by default.<br>
<div>Rob Latham at ANL has more experiences on this feature. He may have some suggestions.</div>
<div><br>
</div>
<div>In the meantime, can you write to a new folder and explicitly set its</div>
<div>Lustre striping count to a larger number, as the total write amount is more</div>
<div>than 300GB? This old fashion setting may give a consistent timing.</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div>Wei-keng </div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 1:27 PM, Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
oh and the pnetcdf version is 1.12.3<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 12:25 PM Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
On my list of things to do in PIO is rewriting the error handling code - but that issue is the same for both cases and</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
so I don't think it would play a role in the difference we are seeing.<br>
</div>
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<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
The lfs getstripe output of the two files is nearly identical, I show only the cesm file here.</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:comic sans ms,sans-serif;color:rgb(56,118,29)">
lcm_layout_gen: 7<br>
lcm_mirror_count: 1<br>
lcm_entry_count: 4<br>
lcme_id: 1<br>
lcme_mirror_id: 0<br>
lcme_flags: init<br>
lcme_extent.e_start: 0<br>
lcme_extent.e_end: 16777216<br>
lmm_stripe_count: 1<br>
lmm_stripe_size: 1048576<br>
lmm_pattern: raid0<br>
lmm_layout_gen: 0<br>
lmm_stripe_offset: 27<br>
lmm_objects:<br>
- 0: { l_ost_idx: 27, l_fid: [0xa80000401:0x3f2ef8:0x0] }<br>
<br>
lcme_id: 2<br>
lcme_mirror_id: 0<br>
lcme_flags: init<br>
lcme_extent.e_start: 16777216<br>
lcme_extent.e_end: 17179869184<br>
lmm_stripe_count: 4<br>
lmm_stripe_size: 16777216<br>
lmm_pattern: raid0<br>
lmm_layout_gen: 0<br>
lmm_stripe_offset: 35<br>
lmm_objects:<br>
- 0: { l_ost_idx: 35, l_fid: [0xc80000401:0x3f32e5:0x0] }<br>
- 1: { l_ost_idx: 39, l_fid: [0xcc0000402:0x3f3162:0x0] }<br>
- 2: { l_ost_idx: 43, l_fid: [0xe80000402:0x3f2f3a:0x0] }<br>
- 3: { l_ost_idx: 47, l_fid: [0xec0000401:0x3f3017:0x0] }<br>
<br>
lcme_id: 3<br>
lcme_mirror_id: 0<br>
lcme_flags: init<br>
lcme_extent.e_start: 17179869184<br>
lcme_extent.e_end: 68719476736<br>
lmm_stripe_count: 12<br>
lmm_stripe_size: 16777216<br>
lmm_pattern: raid0<br>
lmm_layout_gen: 0<br>
lmm_stripe_offset: 16<br>
lmm_objects:<br>
- 0: { l_ost_idx: 16, l_fid: [0x700000402:0x4021eb:0x0] }<br>
- 1: { l_ost_idx: 20, l_fid: [0x740000402:0x4020ae:0x0] }<br>
- 2: { l_ost_idx: 24, l_fid: [0x900000400:0x401f68:0x0] }<br>
- 3: { l_ost_idx: 28, l_fid: [0x940000400:0x401f71:0x0] }<br>
- 4: { l_ost_idx: 32, l_fid: [0xb00000402:0x40220c:0x0] }<br>
- 5: { l_ost_idx: 36, l_fid: [0xb40000402:0x40210b:0x0] }<br>
- 6: { l_ost_idx: 40, l_fid: [0xd00000402:0x402141:0x0] }<br>
- 7: { l_ost_idx: 44, l_fid: [0xd40000400:0x401e90:0x0] }<br>
- 8: { l_ost_idx: 48, l_fid: [0xf00000401:0x401e08:0x0] }<br>
- 9: { l_ost_idx: 52, l_fid: [0xf40000400:0x401e32:0x0] }<br>
- 10: { l_ost_idx: 56, l_fid: [0x1100000402:0x4022e0:0x0] }<br>
- 11: { l_ost_idx: 60, l_fid: [0x1140000402:0x4020a6:0x0] }<br>
<br>
lcme_id: 4<br>
lcme_mirror_id: 0<br>
lcme_flags: init<br>
lcme_extent.e_start: 68719476736<br>
lcme_extent.e_end: EOF<br>
lmm_stripe_count: 24<br>
lmm_stripe_size: 16777216<br>
lmm_pattern: raid0<br>
lmm_layout_gen: 0<br>
lmm_stripe_offset: 51<br>
lmm_objects:<br>
- 0: { l_ost_idx: 51, l_fid: [0x1080000400:0x402881:0x0] }<br>
- 1: { l_ost_idx: 55, l_fid: [0x10c0000400:0x402955:0x0] }<br>
- 2: { l_ost_idx: 59, l_fid: [0x1280000400:0x4027d6:0x0] }<br>
- 3: { l_ost_idx: 63, l_fid: [0x12c0000401:0x402ab2:0x0] }<br>
- 4: { l_ost_idx: 67, l_fid: [0x1480000400:0x402b75:0x0] }<br>
- 5: { l_ost_idx: 71, l_fid: [0x14c0000400:0x4028d2:0x0] }<br>
- 6: { l_ost_idx: 75, l_fid: [0x1680000401:0x402a3b:0x0] }<br>
- 7: { l_ost_idx: 79, l_fid: [0x16c0000402:0x40294d:0x0] }<br>
- 8: { l_ost_idx: 83, l_fid: [0x1880000401:0x40299c:0x0] }<br>
- 9: { l_ost_idx: 87, l_fid: [0x18c0000402:0x402f5e:0x0] }<br>
- 10: { l_ost_idx: 91, l_fid: [0x1a80000400:0x402a16:0x0] }<br>
- 11: { l_ost_idx: 95, l_fid: [0x1ac0000400:0x402bd2:0x0] }<br>
- 12: { l_ost_idx: 0, l_fid: [0x300000401:0x402a2e:0x0] }<br>
- 13: { l_ost_idx: 4, l_fid: [0x340000402:0x4027d2:0x0] }<br>
- 14: { l_ost_idx: 8, l_fid: [0x500000402:0x402a26:0x0] }<br>
- 15: { l_ost_idx: 12, l_fid: [0x540000400:0x402943:0x0] }<br>
- 16: { l_ost_idx: 64, l_fid: [0x1300000402:0x402c10:0x0] }<br>
- 17: { l_ost_idx: 68, l_fid: [0x1340000401:0x4029c6:0x0] }<br>
- 18: { l_ost_idx: 72, l_fid: [0x1500000402:0x402d11:0x0] }<br>
- 19: { l_ost_idx: 76, l_fid: [0x1540000402:0x402be2:0x0] }<br>
- 20: { l_ost_idx: 80, l_fid: [0x1700000400:0x402a64:0x0] }<br>
- 21: { l_ost_idx: 84, l_fid: [0x1740000401:0x402b11:0x0] }<br>
- 22: { l_ost_idx: 88, l_fid: [0x1900000402:0x402cb8:0x0] }<br>
- 23: { l_ost_idx: 92, l_fid: [0x1940000400:0x402cd3:0x0] }<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 12:12 PM Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu" target="_blank">wkliao@northwestern.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div><br>
<div>I can see the file header size of 20620 bytes. Because all attributes are stored</div>
<div>in the header, the cost of writing them should not be an issue. I also see no gap</div>
<div>between 2 consecutive variables, which is good, meaning the write requests made</div>
<div>by MPI-IO will be contiguous.
<div><br>
</div>
<div>If the call sequence of PnetCDF APIs is the same between pioperf and cesm, then</div>
<div>the performance should be similarly. Can you check the Lustre striping settings</div>
<div>of the 2 output files, using command "lfs getstripe"?</div>
<div><br>
</div>
<div>If you set any MPI-IO hints, they can also play a role in performance.</div>
<div>See the example in PnetCDF for how to dump all hints (function print_info().)</div>
<div><a href="https://urldefense.com/v3/__https://github.com/Parallel-NetCDF/PnetCDF/blob/master/examples/C/get_info.c__;!!Dq0X2DkFhyF93HkjWTBQKhk!S2kyuECdrloQfFGddM-B1Y9QnqTEKxfduivqOXqC5UpDlBkIBRYblv--jZO9EebTthfwwDYkKtJkHqMsgmikJ3c$" target="_blank">https://github.com/Parallel-NetCDF/PnetCDF/blob/master/examples/C/get_info.c</a></div>
<div><br>
<div>If all the above checked out right, then using Darshan should reveal more information.</div>
<div><br>
</div>
<div>
<div>BTW, what PnetCDF version is being used?</div>
<div><br>
</div>
</div>
<div>A comment about PIOc_put_att_tc.</div>
<div>* calling MPI_Bcast for checking the error code may not be necessary. PnetCDF does such</div>
<div> check and all metadata consistency check at ncmpi_enddef. If the number of variables</div>
<div> and their attributes are high, then calling lots of MPI_Bcast can be expensive.</div>
<div>
<div><a href="https://urldefense.com/v3/__https://github.com/NCAR/ParallelIO/blob/f45ba898bec31e6cd662ac41f43e0cff14f928b2/src/clib/pio_getput_int.c*L213__;Iw!!Dq0X2DkFhyF93HkjWTBQKhk!S2kyuECdrloQfFGddM-B1Y9QnqTEKxfduivqOXqC5UpDlBkIBRYblv--jZO9EebTthfwwDYkKtJkHqMsyB5l4Jg$" target="_blank">https://github.com/NCAR/ParallelIO/blob/f45ba898bec31e6cd662ac41f43e0cff14f928b2/src/clib/pio_getput_int.c#L213</a></div>
<div><br>
</div>
<div><br>
</div>
</div>
<div>Wei-keng</div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 12:32 PM, Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
Yes, _enddef is called only once. <br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<a href="https://urldefense.com/v3/__https://github.com/NCAR/ParallelIO/blob/main/src/clib/pio_getput_int.c*L128__;Iw!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hw4F6HzDo$" target="_blank">Here</a> is
the code that writes attributes. <a href="https://urldefense.com/v3/__https://github.com/NCAR/ParallelIO/blob/main/src/clib/pio_darray_int.c*L661__;Iw!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwOC-tyLY$" target="_blank"> Here</a> is
where variables are written. <br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
ncoffsets -sg <a href="https://urldefense.com/v3/__http://pioperf.2-0256-1.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwTlZDyu8$" target="_blank">pioperf.2-0256-1.nc</a><br>
netcdf <a href="https://urldefense.com/v3/__http://pioperf.2-0256-1.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwTlZDyu8$" target="_blank">pioperf.2-0256-1.nc</a> {<br>
// file format: CDF-5<br>
<br>
file header:<br>
size = 7804 bytes<br>
extent = 8192 bytes<br>
<br>
dimensions:<br>
dim000001 = 10485762<br>
dim000002 = 58<br>
time = UNLIMITED // (1 currently)<br>
<br>
record variables:<br>
double vard0001(time, dim000002, dim000001):<br>
start file offset = 8192 (0th record)<br>
end file offset = 4865401760 (0th record)<br>
size in bytes = 4865393568 (of one record)<br>
gap from prev var = 388<br>
double vard0002(time, dim000002, dim000001):<br>
start file offset = 4865401760 (0th record)<br>
end file offset = 9730795328 (0th record)<br>
size in bytes = 4865393568 (of one record)<br>
gap from prev var = 0<br>
</div>
</div>
</div>
</blockquote>
<div><br>
</div>
snip</div>
<div><br>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
double vard0064(time, dim000002, dim000001):<br>
start file offset =306519802976 (0th record)<br>
end file offset =311385196544 (0th record)<br>
size in bytes = 4865393568 (of one record)<br>
gap from prev var = 0<br>
}</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
ncoffsets -sg run/<a href="https://urldefense.com/v3/__http://SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-03600.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwdkm0FHQ$" target="_blank">SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-03600.nc</a><br>
netcdf run/<a href="https://urldefense.com/v3/__http://SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-03600.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwdkm0FHQ$" target="_blank">SMS_D_Ln9.mpasa7p5_mpasa7p5_mg17.QPC6.derecho_intel.cam-outfrq9s.20230726_094231_iz24v6.cam.h0.0001-01-01-03600.nc</a> {<br>
// file format: CDF-5<br>
<br>
file header:<br>
size = 20620 bytes<br>
extent = 16777216 bytes<br>
<br>
dimensions:<br>
ncol = 10485762<br>
time = UNLIMITED // (1 currently)<br>
nbnd = 2<br>
chars = 8<br>
lev = 58<br>
ilev = 59<br>
<br>
fixed-size variables:<br>
double lat(ncol):<br>
start file offset = 16777216<br>
end file offset = 100663312<br>
size in bytes = 83886096<br>
gap from prev var = 16756596<br>
double lon(ncol):<br>
start file offset = 100663312<br>
end file offset = 184549408<br>
size in bytes = 83886096<br>
gap from prev var = 0<br>
</div>
</div>
</blockquote>
<div><br>
</div>
snip</div>
<div><br>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
int mdt:<br>
start file offset = 352322552<br>
end file offset = 352322556<br>
size in bytes = 4<br>
gap from prev var = 0<br>
<br>
record variables:<br>
double time(time):<br>
start file offset = 352322556 (0th record)<br>
end file offset = 352322564 (0th record)<br>
size in bytes = 8 (of one record)<br>
gap from prev var = 0<br>
int date(time):<br>
start file offset = 352322564 (0th record)<br>
end file offset = 352322568 (0th record)<br>
size in bytes = 4 (of one record)<br>
gap from prev var = 0<br>
</div>
</div>
</blockquote>
<div><br>
</div>
snip</div>
<div><br>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
double STEND_CLUBB(time, lev, ncol):<br>
start file offset =306872117448 (0th record)<br>
end file offset =311737511016 (0th record)<br>
size in bytes = 4865393568 (of one record)<br>
gap from prev var = 0<br>
}<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 10:35 AM Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu" target="_blank">wkliao@northwestern.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>Can you run command "ncoffsets -sg <a href="https://urldefense.com/v3/__http://file.nc__;!!Dq0X2DkFhyF93HkjWTBQKhk!Rb9IHCtwLvKBflvuPIGfD-peS-Hl1-epxN7yjpgkPoFWdSFS3DFGNkKhfb7WqrC_N0TBJDe-1bKKU_hwCtAtD9k$" target="_blank">file.nc</a>" that shows the sizes
of file header</div>
<div>and all variables? For the cesm case, is _enddef called only once?</div>
<div><br>
</div>
<div>Could you also point me to the program files that call PnetCDF APIs, including</div>
<div>writing attributes and variables?</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div>Wei-keng </div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 11:05 AM, Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
I am using the new ncar system, <a href="https://urldefense.com/v3/__https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwigtcytrsOAAxWXHjQIHVoDD6YQFnoECBcQAQ&url=https*3A*2F*2Farc.ucar.edu*2Fknowledge_base*2F74317833&usg=AOvVaw2aXlWuOfLnua7fFmIgvfoV&opi=89978449__;JSUlJSU!!Dq0X2DkFhyF93HkjWTBQKhk!Xq6u5krREolkIRHG8AL2taDCmg6HsEdgcEoviUVyzqUINi-ipPM1EhtMcJkQfUYghDhutn7DfH5Wjm57wJ9lQhc$" target="_blank">derecho</a>,
which has a lustre parallel file system.</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
Looking at the difference between the two headers below makes me wonder if the issue is with variable attributes?<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
</div>
</div>
</blockquote>
<div><br>
</div>
snip</div>
<div><br>
<blockquote type="cite"><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Aug 4, 2023 at 9:39 AM Wei-Keng Liao <<a href="mailto:wkliao@northwestern.edu" target="_blank">wkliao@northwestern.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Hi, Jim
<div><br>
</div>
<div>Can your provide the test program and the file header dumped by "ncdump -h", if that is available?</div>
<div>Also, what machine was used in the tests and its the parallel file system configuration is?</div>
<div>These can help diagnose.</div>
<div><br>
</div>
<div>
<div>Wei-keng </div>
<div><br>
<blockquote type="cite">
<div>On Aug 4, 2023, at 8:49 AM, Jim Edwards <<a href="mailto:jedwards@ucar.edu" target="_blank">jedwards@ucar.edu</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
I am using ncmpi_iput_varn and ncmpi_wait_all to write output from my model. I have a test program that does nothing but test the <br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
performance of the write operation. Attached is a plot of performance in the model and in the standalone application. I'm looking for <br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
clues as to why the model performance is scaling so badly with the number of variables but the standalone program performance is fine. <br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br>
</div>
<div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(56,118,29)">
<br clear="all">
</div>
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</div>
<span id="m_-6143949282488622199m_-8662804092637909240m_-507956858473461832m_8242488052351017746m_-8733781311756881360m_4857238735649148917m_2599353008599558804m_3752102915513421155m_3416875553179895269m_1419731810550872517m_-4661512969452605678cid:f_lkwn4kse0"><Screenshot 2023-07-27
at 11.49.03 AM.png></span></div>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<br clear="all">
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<br clear="all">
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</blockquote>
</div>
</div>
<br>
</div>
</div>
</blockquote>
</div>
<br clear="all">
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</blockquote>
</div>
<br clear="all">
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote>
</div>
<br clear="all">
<br>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div>
<div>Jim Edwards<br>
<br>
</div>
<font size="1">CESM Software Engineer<br>
</font></div>
<font size="1">National Center for Atmospheric Research<br>
</font></div>
<font size="1">Boulder, CO</font> <br>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote></div><br clear="all"><br><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div><div>Jim Edwards<br><br></div><font size="1">CESM Software Engineer<br></font></div><font size="1">National Center for Atmospheric Research<br></font></div><font size="1">Boulder, CO</font> <br></div></div>