[Wylug-discuss] Delurk and how not to use rsyncApa

[Richard Ibbotson]

On Wednesday 22 June 2011 14:11:20 John Hodrien wrote:
> On Wed, 22 Jun 2011, Richard Ibbotson wrote:
> > scp -r /home/james/name_of_the_folder 192.168.1.50:/home/james
> > scp somefile.txt ... or ....
> > scp somefile.doc
> > 
> > the 192.168.1.50 mentioned above is the IPV4 IP address of your
> > workstation or netbook.  Whichever.  Nice thing about scp is that
> > it quickly copies everything over without too much CPU overhead.
> 
> But it's impractical to use as a sync tool, as it'll copy
> everything rather than just the files you want.  scp also
> incredibly slow when you're copying a lot of small files, as you a
> get a per-file latency hit.  If you're just trying to copy a lot
> from one machine to another, tar over ssh is considerably faster
> (and link speed and file type depending, you can throw a bzip/gzip
> in there too).  scp also doesn't preserve ownership.  CPU overhead
> can actually be an issue with scp, as you have to have quite a
> fast CPU to not find you're CPU limited on a gigabit network (and
> you'll find that's a serial bottleneck, so having lots of cores
> doesn't help).  Probably tar over rsh/nc would be the fastest if
> you're just trying to shovel data.

I suppose so.  I just prefer scp myself.  When I started to use Rsync 
I was in touch with Andrew Tridgell who had just written the software.  
There were lots of bugs.  Each new release produced other bugs.  So, 
as I say, I prefer scp.  Later versions of Rsync seem to be more 
reliable.  I used to use Rsync to do backups for local companies in 
Sheffield.  It did the job mostly.


-- 
Richard