On Wed, Oct 01, 2003 at 03:25:27PM -0700, Pat Lashley wrote:
> --On Wednesday, October 01, 2003 13:22:36 -0400 Chuck Swiger 
> <[EMAIL PROTECTED]> wrote:
> >Jamie wrote:
> >[ ... ]
> >>    I don't know what the actual rationale is for this. Can anyone
> >>    explain why it is oftentimes better to tar something rather than
> >>using cp when copying directories and their contents?
> >
> >tar handles symbolic links properly, whereas cp will "copy through" the
> >contents of the link.
> Another technique is 'cd /source ; find . -print | cpio -pdmv /dest'.
> But none of the built in tools seem to preserve links, flags, and
> sparseness.  If you want as close to a true copy as possible, check
> out the cpdup port.

using tar | tar instead of cp -r is usually faster because it makes
more efficient use of disk I/O, because reads and writes are queued up
at the same time, from the two processes) whereas cp -r reads and
writes chunks sequentially (it's actually implemented using mmap'ed
memory, which gains some efficiency, but it's still a sequential
process because there's only one single-threaded cp running).


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