[Darshan-users] Unexpected Darshan I/O characterization running IOR BM

Cormac Garvey cormac.t.garvey at gmail.com
Tue Nov 20 18:58:35 CST 2018


Hello,
I recently installed Darshan 3.1.6 on Microsoft Azure VM running Centos 7.4.

I got an unexpected result using Darshan to characterize the I/O for an IOR
benchmark
experiment.

export
LD_PRELOAD=/avere/apps/spack/linux-centos7-x86_64/gcc-4.8.5/darshan-runtime-3.1.6-daohky4yevagxajjl33lwk472lcgn6g4/lib/libdarshan.so
BLOCKSIZE=256M
mpirun -np 8 ior -a POSIX -B -r -k -z -v -o $FILEPATH -i 2 -m -t 32m -b
256M -d 1

After the job completed, a Darshan log file was created, the resulting text
report (darshan-parser_ior_read_shared.out, its attached) was generated
using the following command

darshan-parser  --all
testuser_ior_id22-20-80229-14589323501426222819_1.darshan >&
darshan-parser_ior_read_shared.out

The above IOR benchmark is a read only benchmark to a shared file system,
but the resulting darshan report indicates there are no READ operations?

Any ideas why the resulting Darshan resport has no read operations? (Note
if I add a -w option to the above IOR benchmark  (i.e do a write and read
to a shared filesystem, darshan only
reports the writes and not reads?)

Any help would be appreciated,
Thanks for your support,
Cormac.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/darshan-users/attachments/20181120/bf006dc4/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: darshan-parser_ior_read_shared.out
Type: application/octet-stream
Size: 36089 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/darshan-users/attachments/20181120/bf006dc4/attachment-0001.obj>


More information about the Darshan-users mailing list