[X-Unix] Re: Pokey LAN transfers (Resolved + a followup)

[Wing Wong]

Hardly a "duh" moment at all. Good catch!

Wing

On 1/2/08, Richard Hartman <seasoft at west.net> wrote:
> For those of you with interest in this goat rope, there has been a
> development that isn't surprising in hindsight; in fact most of you
> will simply think "well, duh!" But, for any other noobs struggling to
> make sense of it all, consider this:
>
> I was having sporadic & bizarre trouble with DVD burns on my "system
> #2" MacBookPro (see below; running Leopard) and after much
> troubleshooting, tracked the problem down to some errant system &
> plist files.
>
> The MBPro Leopard had been a clean install, not an upgrade, but it
> got a "migration assist" from my existing Tiger system. On the
> suspicion that the migration might have caused other issues, I erased
> & re-installed & updated Leopard on the MBPro, AND installed every
> necessary piece of software from scratch (i.e., NO migration).
>
> Lo and behold, finder copies of the kind that formerly went at 25
> megabits per second are now shooting across at full speed (100 mbps).
>
> So, although there was no indication in my console or system logs
> that anything was awry before the reinstall, in fact that pesky
> migration assistant evidently produced some sort of havoc. The Finder
> now copies as fast as rsync.
>
> Moral, for me: Never, ever use migration assistant for major system
> upgrades; it oughta be a law...
>
> Richard
>
> On Dec 27, 2007, at 11:49 AM, Richard Hartman wrote:
>
> > Thanks to Wing Wong, Nick Scalise, David Ledger and Brian Medley
> > for their thoughtful responses. For some reason, Wing Wong's
> > detailed response didn't make it to the list and is reproduced
> > (far) below.
> >
> > Here is a summary of what I learned:
> >
> > The overhead on my setup of mounting a volume on the desktop (via
> > AFP) is evidently enormous:
> >
> > - Mounting a LAN volume on the local desktop and then using cp on a
> > large (2GB) file using a terminal window (copying from mounted LAN
> > volume to internal disk drive)  produced transfer rates of only
> > about 25 megabits/sec.
> >
> > - Unmounting the LAN volume and instead using scp or rsync (and the
> > IP address of the source mac) produced the expected transfer rate
> > of 100 megabits/sec, which was the speed limit expected by the
> > slowest network element in the loop (the 100 mbps nic on one of the
> > macs).
> >
> > Regards,
> >
> > Rich
> >
> >> On Dec 26, 2007 1:54 PM, Richard Hartman < seasoft at west.net> wrote:
> >> I'm looking for guidance on how best to copy large data sets between
> >> macs on a network (Finder, terminal cp, other?).
> >>
> >> The setup: Copying from mac #1 (a 2006 iMac running 10.4.11 with
> >> built-in 100bps ethernet) to mac #2 (a recent PBPro running 10.5.1
> >> with built-in Gigabit ethernet). Macs connected by a Gigabit netgear
> >> switch.
> >>
> >> I had hoped to get sustained transfers between these two macs of
> >> 50-70 mbps (throttled by the rate-limiting 100 mbps iMac capability).
> >>
> >> However, copying a single 2 GByte file, by mounting the (Tiger) imac
> >> on the (Leopard) MBPro desktop and using terminal "cp" command from
> >> the MBPro terminal, results in a sustained transfer rate of only
> >> about 2.5 mB/sec (25 mbps).
> >>
> >
> >
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-- 
Wing Wong
wingedpower at gmail.com