Date: Fri, 4 Feb 2005 18:54:34 +0100 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: RW <list-freebsd-2004@morbius.sent.com> Cc: freebsd-geom@freebsd.org Subject: Re: Encrypted DVDs beyond 2GB Message-ID: <20050204175434.GH27596@darkness.comp.waw.pl> In-Reply-To: <200502041743.21047.list-freebsd-2004@morbius.sent.com> References: <200502041743.21047.list-freebsd-2004@morbius.sent.com>
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[-- Attachment #1 --] On Fri, Feb 04, 2005 at 05:43:18PM +0000, RW wrote: +> Some time ago I asked about creating encrypted data CDs, and someone suggested +> using mdconfig to create a file backed md device, encrypted with gdbe, and +> then burning the backing file to CD. +> +> That all works fine, but when the same technique is tried on DVDs, you run +> into the problem that FreeBSD 5.3 can't handle a file bigger that 2GB on an +> iso9660 filesystem. If you install the development version of mkisofs, it is +> possible to burn a DVD containing a file of up to 4GB. Windows 98 can read +> the file off the disk, but FreeBSD can't do anything with it. +> +> Using 2 files and having the data mounted at two separate points would be a +> bit clumsy. Does anyone have a better idea? I'm just doing it now, so few random advices. - With DVD+RW you don't need iso9660 file system. What you need to do is to format it: # dvd+rw-format /dev/cd0 # cdcontrol eject # cdcontrol close create even UFS2 on it: # newfs -U /dev/acd0t01 mount it and just copy files there. - GBDE is very, very slow on DVDs for me. Practicaly unusable. I wrote a GEOM class for simple encryption which don't have to read key sectors, data sectors, etc. So there is no performance difference for me. - If you want to use many md(4) file-backed devices, you can use gconcat(8). If you create concatenated device with 'create' subcommand, no on-disk metadata is used, so it work like one big file. - You can try growfs(8) from sysutils/dvd+rw-tools. -- Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFCA7baForvXbEpPzQRAthJAJ4522EmJB4NSydXA/egG/q6gs6gEgCgobSe 7Gts2Ttue2QyR5RHQ0ZU3o0= =b9V/ -----END PGP SIGNATURE-----
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