[svlug] help transfering data over 1394 cable

[Scott Hess]

I think most everything has been addressed in the thread, so ...

On Tue, May 6, 2008 at 3:04 PM, Christian Einfeldt <einfeldt at gmail.com> wrote:
> On Tue, May 6, 2008 at 2:33 PM, Scott Hess <scott at doubleu.com> wrote:
> > I'd just run rsync between them and leave it alone for awhile,
> > monitoring by running df or du periodically on the target.
>
> Sorry to ask a stupid question, but what are the commands there? Just
>
> $ rysnc

"man rsync" to find out how to use rsync.  You'll be doing something like:

   rsync -aHS /dir/to/copy/ user at other_machine:/copy/of/dir/

rsync will use ssh to connect to user at other_machine, and then copy any
files from /dir/to/copy/ on the local machine to /copy/of/dir/ on the
remote machine.  [-a for "archive", which keeps permissions and
ownership, -H for "retain hardlinks", -S for "handle sparse files".
You can omit user@ if the user is the same on both machines.]

The cool thing is that if you run it again, rsync will only copy over
stuff that changed.  If nothing changed, it might run for a couple
minutes (checking everything out), and then exit.

> and
>
> $ df

df will tell you disk usage.  The rsync above will run for a fairly
long time if you have 1.5T, regardless of your network.  So you might
login to the remote machine and run df every once and awhile (like
after supper, then after breakfast :-) and watch that stuff is being
copied over.    Again, "man df" to find out various flags.

> and
>
> $ du

du tells you how much space a directory is taking up.  "du
/directory/to/size".  So you can login to the remote machine and run
du on the target directory to see it getting bigger and bigger.
Again, "man du" to find out various flags.

> > You might try plugging a crossover Ethernet cable directly between the
> > boxes to make sure nothing else is screwing your networking up.
>
> I can get a crossover cable and be back here at my office within 4 hours.
> If you don't mind letting me know what I should do when the xover cable is
> in place, that would be great.  Please bear in mind that i have only one
> ethernet jack on each machine, so I would need to be off of the Internet
> while deploying this diagnostic tool.

Sounds like a crossover might not be worthwhile, then.  You'd also
probably have to tweak the network setup a bit to get it working.

> > Having a 16T box implies that it's perhaps got 1T drives?  You might
> > be better off just pulling one of those drives and using a sneakernet
> > to copy things over.
>
> Not really a tenable solution, because I need to move lots and lots of data
> back and forth frequently.  Thanks for the thought, though!

If you mount the drive and use rsync locally to copy the data, then
move it back to the other box, later you can rsync between the boxes
and it will know not to re-copy the data that was already copied.  But
if you can wait for the data to copy over the network, that's probably
safer and less error-prone.

-scott