Slowdown when copying large files (PR#8617)

[Jeremy Allison]

peloy at ven.ra.rockwell.com wrote:
> 
> Andrew Tridgell <samba-bugs at samba.anu.edu.au> wrote:
> 
> > The Windows98 explorer (and possibly other programs) incorrectly set the
> > "sync" bit in write requests to network shares. This causes an enormous
> > slowdown as Samba (quite correctly) does a fsync() on the file after each
> > write. Combine this with the fact that Windows98 explorer uses very small
> > write sizes (around 1.5k) and you get really terrible results.
> 
> Andrew, but if it is Windows 98 the one that is screwing things up,
> wouldn't this slowdown be seen when the server is something else, like
> Windows 95/NT, etc.?
> 

Apparently not - according to one of JohnT's technical
contacts at MS - doing a fsync on a file in NT isn't the
same as a UNIX fsync, but only *schedules the write to
be done* !

I will add this option before 1.9.18p9 ships - the only
question is - should it be on or off by default ?

Cheers,

	Jeremy.


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