[R] save.image() issue resolved - I hope

[ripley@stats.ox.ac.uk]

On Sun, 14 Apr 2002, Prof Brian D Ripley wrote:

> On Sat, 13 Apr 2002, Marc R. Feldesman wrote:
>
> > I've been combing through logs I keep of all my activities.  I've found a
> > possible correlation between the save.image() problem I'm having and one
> > particular event.
> >
> > My system has a rewriteable DVD drive.  I keep a 4.7 GB DVD/RW disk in the
> > E: drive and have a system scheduler synchronize the contents of the g:
> > drive with the e: drive every Friday night.  Interestingly, both times I've
> > discovered the save.image() problem have been on Saturday mornings.  I
> > discovered that if I copy the entire data directory on the g: drive to a
> > new directory on the same drive, I don't have the save.image()
> > problem.  However, if I manually synchronize the two drives (G -> E),
> > save.image() fails.  The only difference I can see between the data
> > directory *before* synchronization and *after* synchronization is that
> > synchronization "unsets" the archive bit.  If I make a new directory, the
> > "archive bit" is set and save.image() works.
> >
> > I'm not sure why this is a problem for the routines in R -- it certainly
> > doesn't seem to be a problem with other programs -- but either avoiding
> > synchronization (a straight copy also works, but copies far more than is
> > actually necessary), or manually resetting the archive bit before using R
> > seems to "solve" the problem.

I can't reproduce any problem with the archive bit manually unset.

> Renaming via the ISO C call is an unusual thing for Windows programs to
> use.  The Windows implementation is not POSIX-compliant.  I'll see if there
> are better ways to do this under Windows (but not for 1.5.0).  Sometimes
> Explorer can works with files that tools ported from Unix think are in use.

It seems that most Windows applications would use DeleteFile/MoveFile (not
unlink/rename) and Windows NT (but not 9X) supports renaming existing
files using MoveFileEx.  Looks like it would be worth exploring the latter
for 1.6.x.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._