Re: [Xen-users] shrink or grow disk image?

[John Haxby <john.haxby@xxxxxxxxxx>]

John Haxby wrote:
> Of course, if your original file is sparse then shrinking isn't going 
> to actually free disk space but as you've just copied it (using, 
> presumably, cp) then you've filled all the holes with zeroes.   If you 
> copy the file with tar and the --sparse options then the holes won't 
> get filled in and you won't be using space that you don't need.  I 
> suspect, though I haven't tried it, that copying a file with lots of 
> zero-filled blocks using tar --sparse will convert those blocks into 
> holes.  Does that help?
On Fedora 8, at least, cp handles sparse files quite nicely and "cp 
--sparse=always" seems to do a good job of turning blocks of zeros into 
holes.
You learn something new every day.

jch

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users