andrzej zaborowski wrote:
On 02/08/06, Brad Campbell <[EMAIL PROTECTED]> wrote:
ZIGLIO, Frediano, VF-IT wrote:
> Hi,
> well, this is not a definitive patch but it works. The aim is to be
> able to wipe the disk without allocating entire space. When you wipe a
> disk the program fill disk with zero bytes so disk image increase to
> allocate all space. This just patch detect null byte writes and do not
> write all zero byte clusters.
>
I've been giving this some pretty heavy testing over the last week
and can say I've not noticed any
negative performance impact or any other adverse side effects, not to
mention the speedup when doing
re-packing (which I do fairly regularly on both ext3 and ntfs guest
filesystems).
While I'm here does anyone know of a simple program, either dos or
linux based for wiping unused
space on fat filesystems? The only ones I've found so far have been
windows based.
I don't know if you mean just zeroing unused parts or reordering the
data and stuff like defragmentation. If you mean the former, there's a
universal method:
dd if=/dev/zero of=xxx; rm xxx
where xxx is a path to a new file on the filesystem, which must be
mounted. It will creata a zero filled file there, which will fill all
It would be wise to sync as well, to ensure the zeros are actually written
and not stored in cache where the rm would remove them:
dd if=/dev/zero of=xxx; sync; rm xxx
availiable space, and remove the file afterwards. I used this when I
needed to send filesystem images through internet so that they
compressed well.
If you add dd=<a-big-number-here> it might take less time to write the
file.
Regards,
begin:vcard
fn:Nigel Horne
n:Horne;Nigel
org:NJH Music
email;internet:[EMAIL PROTECTED]
x-mozilla-html:FALSE
url:http://www.bandsman.co.uk
version:2.1
end:vcard
_______________________________________________
Qemu-devel mailing list
Qemu-devel@nongnu.org
http://lists.nongnu.org/mailman/listinfo/qemu-devel
