Changes between Version 8 and Version 9 of doc/app/runs

Timestamp:

Jul 3, 2017 3:22:34 PM (8 years ago)

Author:

raasch

Comment:

--

doc/app/runs

@@ -39 +39 @@
 }}}
 However, after the file produced by the previous job was read in by the model and after the local file BINOUT was produced at the end of the job, the restart job does not overwrite this permanent file ({{{.../abcde_d3d}}}) with the new data. Instead of that, it is examined whether already a permanent file with the name {{{.../abcde_d3d}}} exists when copying the output file (BINOUT) of '''mrun'''. If this is the case, BINOUT is copied to the file {{{.../abcde_d3d.1}}}. Even if this file is already present, {{{.../abcde_d3d.2}}} is tried etc. For an input file the highest existing cycle of the respective permanent file is copied. In the example above this means: the initial run creates the permanent file {{{.../abcde_d3d}}}, the first restart run uses this file and creates {{{.../abcde_d3d.1}}}, the second restart run creates {{{.../abcde_d3d.2}}} etc. After completion of the job chain the user can still access all files created by the jobs. This makes it possible for the user for example to restart the model run of a certain job of the job chain again.\\\\
-Therefore restart jobs can not only be started automatically through '''mrun''', but also manually by the user. This is necessary e.g. whenever after the end of a job chain it is decided that the simulation must be continued further, because the phenomenon which should be examined did not reach the desired state yet. In such cases the '''mrun''' options completely correspond to those of the initial call; simply the {{{"#"}}} characters in the arguments of options {{{-r}}}, {{{-i}}} and {{{-o}}} must be replaced by {{{"f"}}}. 
+Therefore restart jobs can not only be started automatically through '''mrun''', but also manually by the user. This is necessary e.g. whenever after the end of a job chain it is decided that the simulation must be continued further, because the phenomenon which should be examined did not reach the desired state yet. In such cases the '''mrun''' options completely correspond to those of the initial call; simply the {{{"#"}}} characters in the arguments of options {{{-r}}}, {{{-i}}} and {{{-o}}} must be replaced by {{{"f"}}}.\\\\
+
+= Handling of large binary restart- or output-files =
+
+In case of very large files, the copy of data from and to PALM's temporary working directory may need a long time. The CPU cores requested for the job run idle during that time and may consume significant amount of the job time without doing anything. The time required for copying can be spared by using a file link instead of copying the data.
+{{{
+   cp large_local_file  large_permanent file    # may take long time
+   ln  ............                             # is done immediately, i.e. requires almost no time
+}}}
+You can tell '''mrun''' to use {{{ld}}} instead of {{{cp}}} by giving the file attribute {{{ln}}} in the respective file connection statement:
+{{{
+bla
+}}}
+However, performing a link requires that the link to a TARGET file with the name LINK_NAME must be located on the same physical file system as the TARGET file ...