Re: rsync and network file transfer speeds

Joshua Jung sez:
....
The short and sweet of my questions is this:

Assuming our transfer speeds are broadband level, will it be faster to
run the standard rsync algorithm or just do a quick check on the time
stamps of the files on client and server and just upload the entire file
(with zipping of course) if the time-stamps are different?

If you can guarantee that the clocks on both ends are always in sync
(ntp will do that, most of the time), and both ends are in the same
time (and DST) zone, yes: a size + timestamp check is going to be
faster. In general you cannot trust a random internet host's clock,
hence the clever algorithms.

Any website links or data on the speed of rsync on current
machines/connections would be greatly appreciated. Also, if there is any
other option besides rsync, that would be sweet as well!

We're using rsync routinely on a 100Mb/s LAN, with a couple of pretty
slow machines (e.g. a Sun Ultra 10). The only problem is that rsync
seems to be very sensitive to network glitches -- most protocols will
recover from 1-2 sec. loss of connectivity just fine, rsync usually
doesn't. (Not what you'd expect from something designed for dial-up
connections.)

Dima
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