On purpose slow copy support?

jw schultz jw at pegasys.ws
Fri Sep 26 07:16:34 EST 2003


On Thu, Sep 25, 2003 at 02:04:19PM -0700, Dan Stromberg wrote:
> On Thu, 2003-09-25 at 14:01, jb at dslreports.com wrote:
> > I'd like to use rsync on a production box that has a great deal of
> > memory-cached filesystem in use at all times. Is there any way, or any
> > other tool, that will do a "slow" copy? purposefully not busting the
> > cache by copying things as fast as possible?
> > 
> > "nice" does not work, of course, as that is a cpu scheduling control.
> > What I want is basically lowest-priority or "background" I/O.
> > 
> > thanks
> 
> strace oughta slow it down a bit.
> 
> If that's not enough, it's not hard to modify strace to usleep a while
> on various syscalls.  I did it once for read/write/send/recv, but it
> never made it into the mainline.  :(

I suppose you could also use LD_PRELOAD to insert delays.  I
have heard of using --bwlimit to reduce the impact on file
I/O.




-- 
________________________________________________________________
	J.W. Schultz            Pegasystems Technologies
	email address:		jw at pegasys.ws

		Remember Cernan and Schmitt



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