Parallel rsync's for better Performance.

[Hendrik Visage]

On Wed, Oct 28, 2009 at 6:24 PM, Matthias Schniedermeyer <ms at citd.de> wrote:
> No. That's a fundamental problem with ANY rotating media device.
>
> I don't say say that you can't build something for the people that have
> that kind of hardware, or that are constrainted by high bandwidth &
> latency network connections (You don't need it for low bandwidth and/or
> low latency). But it would be utterly useless for the other 95-99% of
> rsync users.

Hmmm.... I do disagree a tad here.

High performance SAN storage systems is not uncommon anymore, and some
of the command queue stuff also makes it not that bad... that said,
the storage sizes and amount of files+directories does make this
something to consider... but them again, not everybody have 16-384GB
per server image.

I've been in the situation more than once where I have the RAM and the
back end I/O system, and the latency communications between the two
sites needed the additional rsync TCP/IP streams.

And yes, high latency is defined in these cases >10ms (~20-30km distance)
And yes, I've seen it needed/usefull over GigE between two machines
directly connected too :(