File system error occurred. Error number 3029.

Our operators run a process each week day requiring from one to ten files
on our IFS to be processed. This process has been running reliably for
about
a year. Yesterday, the process failed repeatedly, receiving "Error number
3029."
when attempting to process a file on the IFS using the QP0L_ProcessSubtree
api (thank you to Scott Klement).

This message was received by an SQLRPGLE module that is attempting to:

1) use CPYFRMIMPF to copy data to a System i work file.

2) use MOV to move the IFS file to an error or no-error directory,
depending on results in step 1).

Message text for CPE3029 is: "Resource busy."

The confusing thing to me is why the resource busy message would prevent
completion of step 1), but allow the "busy resource" to be moved in step
2).

Attempting to copy/cut file(s) into the particular IFS directory used by
this
application caused System i Navigator to open a dialog box indicating
the operation had failed. The file(s) to be "cut and paste" into this
directory
was lost.

Using MS Excel to copy a file into the particular IFS directory worked,
but
required two to three minutes to complete.

I have not yet identified any relevant changes to system or programs.

Other business applications using other IFS directories during that time
appear
to have run normally,

This morning, so far, the "Resource busy." problem seems to have been
resolved.

I have found a thread suggesting: " RLSIFSLCK
OBJ('/mydir/mysubdir/myfile.csv') "

I have reviewed midrange list discussions on CPE3029/resource busy, but,
as stated above,
am not certain if the busy resource is the file object or the
directory/folder.

I welcome suggestions on how to research, analyze or avoid this problem.