Date: Sun, 08 Jul 2007 10:37:06 -0700 From: Darren Pilgrim <freebsd@bitfreak.org> To: Michael Eubanks <mse0206@yahoo.com> Cc: freebsd-chat@freebsd.org Subject: Re: compressed HDD image using dd...clearing unused blocks Message-ID: <469120C2.50205@bitfreak.org> In-Reply-To: <669580.92520.qm@web58104.mail.re3.yahoo.com> References: <669580.92520.qm@web58104.mail.re3.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Michael Eubanks wrote: > Hello all, > > I am updating a system that has been around for some > time now. I would like to make a compressed disk > image after the final setup is complete, although, I'm > guessing that the unused blocks will not allow me to > compress the image as well as I could with a > previously clean disk (considering the disk has been > in use for some time now). Is there a way to do this > - zero out unused blocks to optimize compression? I > generally do this with Windows machines using the > cipher command (killing cipher after it has finished > writing zeroes). After running cipher I use dd to > create a compressed HDD image for later use. I'd like > to be able to do the same with FreeBSD. In my experience, using dd to create images of UFS/UFS2 volumes is problematic, though I can't qualify that. It's better to use an archival program like dump or tar, IMO. That approach also gets you a restored volume with no fragmentation.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?469120C2.50205>