Dear OMPI Users,
I have installed BLCR(0.8.2) and OpenMPI(1.4.2) successfully. But now I met a problem when I take a checkpoint. I run CG NPB(NPROCS=16, two nodes: blade02 & blade04, CLASS=C, NFS: $HOME & /opt are shared) BLCR configure: ./configure �Cprefix=/opt/blcr �Cenable-static OpenMPi configure: ./configure �Cprefix=/opt/ompi �Cwith-ft=cr �C with-blcr=/opt/blcr �Cenable-static (I didn’t add ‘enable-ft-thread’ param for I think it might affect the performance. Is it right?? And mpi-threads are enabled by default, so I didn't add ‘enable-mpi-threads’ param) And Can anyone tell me these two params will make the checkpoint time shorter or longer? Our blades use NFS. $HOME and /opt are shared. The checkpoint file is created in the $HOME directory by default. Will it cause the long checkpoint time??? In $HOME/.openmpi/mca-params.conf: crs_base_snapshot_dir=/tmp/ snapc_base_global_snapshot_dir=$HOME/ompi-cr-file snapc_base_store_in_place=0 Then in mpirun terminal: mpirun -machinefile mf -am ft-enable-cr -n 8 ./cg.C.8 In checkpoint terminal: ompi-checkpoint --status 11133 [blade02:11171] Requested - Global Snapshot Reference: (null) [blade02:11171] Pending - Global Snapshot Reference: (null) [blade02:11171] Running - Global Snapshot Reference: (null) [blade02:11171] File Transfer - Global Snapshot Reference: (null) In mpirun terminal: -------------------------------------------------------------------------- WARNING: Could not preload specified file: File already exists. Fileset: $HOME/ompi-cr-file/ompi_global_snapshot_11133.ckpt/0 Host: blade02 Will continue attempting to launch the process. -------------------------------------------------------------------------- [blade02:11133] 3 more processes have sent help message help-orte-filem-rsh. txt / orte-filem-rsh:get-file-exists [blade02:11133] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages How to disable the ‘preload’ and how to solve this problems. Thanks. Btw, when there is no mca-param.conf, and the checkpoint file is placed in $HOME directory by default, I can checkpoint successfully. BUT, it takes a very very long time to checkpoint. With no checkpoint, CG runs about 100s, but with checkpoint, it runs 300s. 200% overhead ratio. WHY? Regards Whchen
