Ah, Ok.  This is the problem then.  The log directory has to be on a shared file system (e.g. nfs, lustre, etc.) that is visible to all nodes.  The log is created and written using collective I/O operations, so all of the ranks need to be able to access the same file simultaneously. I'll open a ticket to investigate if there is a way to produce a more helpful error message in this case. thanks, -Phil On 6/21/21 5:50 PM, Hassan Asghar wrote:

it is not shared directory, but i have install the same version of darshan on the other nodes as well.

-- Regards, *Hassan Asghar* MS Computer Science Mobile: +92-321-1741755 Personal Website: http://bit.ly/2OQ0egs <http://bit.ly/2OQ0egs> Google Scholar: https://bit.ly/3lVYuxF <https://bit.ly/3lVYuxF>

On Mon, Jun 21, 2021 at 10:30 PM Phil Carns <[email protected] <mailto:[email protected]>> wrote:

Hi Hassan,

Is /darshan-logs/ a shared directory?

thanks,

-Phil

On 6/21/21 1:04 PM, Hassan Asghar wrote:

...

Yes, I have set the log path and all permission are given when i run program on local machine it execute successfully but when i exceute on three nodes it show error.

On Tue, 22 Jun 2021, 1:18 am Harms, Kevin, <[email protected] <mailto:[email protected]>> wrote:

Hassan,

  did you create the  /darshan-logs directory? Looks like it might not be writeable.

  try: /darshan-logs/2021/6/21

  if you want to try a quick test, set DARSHAN_LOGFILE to the path/name of the log, like:

  DARSHAN_LOGFILE=/path/I/can/write/to/logfile.darshan

kevin

________________________________________ From: Darshan-users <[email protected] <mailto:[email protected]>> on behalf of Hassan Asghar <[email protected] <mailto:[email protected]>> Sent: Monday, June 21, 2021 12:35 AM To: [email protected] <mailto:[email protected]> Subject: [Darshan-users] Logs not generated inspite throwing warning message

I am running darshan with mpich on a three-node cluster and my job executed successfully but not generated logs. error warning is given below at the end of the execution.

[haxxanasghar@gpuserver2 ~]$ mpiexec -n 64 -f machinefile -env LD_PRELOAD /usr/l                              ocal/lib/libdarshan.so ./MADbench2 640 80 4 8 8 4 4

MADbench 2.0 IO-mode no_pe = 64  no_pix = 640  no_bin = 80  no_gang = 4 sblocksize = 8  fblocksize =                         8  r_mod = 4  w_mod = 4 IOMETHOD = POSIX  IOMODE = SYNC  FILETYPE = UNIQUE REMAP = CUSTOM

S_cc         0.02   [      0.02:      0.03] S_bw         0.01   [      0.01:      0.01] S_w          0.03   [      0.03:      0.04]           ------- S_total      0.07   [      0.07:      0.07]

W_cc         0.04   [      0.03:      0.05] W_bw         0.22   [      0.20:      0.23] W_r          0.02   [      0.02:      0.02] W_w          0.01   [      0.01:      0.01]           ------- W_total      0.28   [      0.28:      0.29]

C_cc         0.01   [      0.01:      0.01] C_bw         0.00   [      0.00:      0.00] C_r          0.01   [      0.01:      0.01]           ------- C_total      0.02   [      0.02:      0.02]

dC[0] = 0.00000e+00 darshan_library_warning: unable to create log file /darshan-logs/2021/6/21/haxxa  nas_MADbench2_id29484-29484_6-21-52165-1341319014666854881.darshan_partial. [haxxanasghar@gpuserver2 ~]$

-- Regards,

Hassan Asghar MS Computer Science Mobile: +92-321-1741755 Personal Website: http://bit.ly/2OQ0egs <http://bit.ly/2OQ0egs> Google Scholar: https://bit.ly/3lVYuxF <https://bit.ly/3lVYuxF>

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