Rsync: Re: patch to enable faster mirroring of large filesystems
dwd at bell-labs.com
Wed Nov 28 08:34:15 EST 2001
On Tue, Nov 27, 2001 at 02:34:22PM -0500, Lenny Foner wrote:
> I know you're trying to get reliable statistics so it's clear what
> sort of performance we're talking about here. But may I respectfully
> suggest that -having- to be so careful about whether optimization
> actually got turned on is a clue that there is still a big problem
No, the difficulty of turning on the optimization is irrelevant because the
optimization is no longer in the current version of rsync. It is only
needed to do the performance test which is a one-time thing.
You seem to be missing my point. I agree that --files-from is useful even
if it has no impact or even negative impact on performance. Nevertheless,
I want to know what the impact on performance will be compared to using an
explicit include-from list, and I am bartering my volunteer effort of
developing the code for someone else's volunteer effort of doing
performance tests of the old optimized case which I expect to be
practically identical to the performance of --files-from. I personally
don't need --files-from because the --include-from list is working fine for
me, so I need extra motivation to put some time into it. I think it has to
be done much like that optimization was done and since I wrote the
optimization in the first place I expect it will probably be more efficient
for me to do it than it would be for somebody else to do it; otherwise I'd
probably just say forget it and wait for somebody else to write the code.
... [ranting deleted] ...
> P.S. Would --files-from= reduce rsync's large memory consumption
> as well, or does it still imply rsync caching some info about every
> file it sees during its entire run, and never flushing this info until
> the end?
I'm pretty sure that rsync won't use up memory for excluded files so it
would make no difference.
- Dave Dykstra
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