Re: unionfs

From: Jörn Engel
Date: Tue Mar 16 2004 - 15:49:00 EST


On Tue, 16 March 2004 15:40:24 -0400, Horst von Brand wrote:
> >
> > $ cp -cr dir1 dir2
> >
> > Behaves similar to 'cp -lr', but creates COWs instead of hard links.
> > Can take a few seconds to create the directories, but not minutes.
>
> Why does it magically take less time? The work done (recursing, fiddling
> with directories, syscalls, ...) is nearly the same.

joern@limerick:~$ time cp -lr /usr/src/linux/ /tmp/linux

real 0m22.356s
user 0m0.167s
sys 0m1.480s
joern@limerick:~$ rm -r /tmp/linux/
joern@limerick:~$ time cp -r /usr/src/linux/ /tmp/linux

real 1m44.147s
user 0m0.499s
sys 0m7.987s

'nuf said, eot.

Jörn

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