Date: Mon, 9 Sep 2002 11:57:42 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Charles Peterman <cjp@sandstorm.net> Cc: hackers@FreeBSD.ORG Subject: Re: DVD-RAM: multi-session writing Message-ID: <20020909115741.A39823@panzer.kdm.org> In-Reply-To: <200209091334.28200.cjp@sandstorm.net>; from cjp@sandstorm.net on Mon, Sep 09, 2002 at 01:34:28PM -0400 References: <200209091334.28200.cjp@sandstorm.net>
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On Mon, Sep 09, 2002 at 13:34:28 -0400, Charles Peterman wrote: > > FreeBSD 4.5. > Hitachi DVD-RAM drive > > I have to support writing files to a DVD-RAM in a Windows compatible mode. > Normally I would treat the thing as a slow HD and read and write at my > leisure, but Windows does not play nicely with UFS. So I came upon the > solution of writing an ISO image out to the disk, like so: > > readcd dev=$DVDRAM_SCSI_ID -w f=image.iso. > > Now this works and is portable, but it has an unfortunate side effect. If I > attempt to write another image out, I overwrite the existing data. > > So, there are three possible solutions: > > 1. Move to UDF, (works for me, but management is scared of anything labelled a > "kernel change") FreeBSD's UDF code doesn't have write support yet, I don't think. You'd have to use something like mkisofs to make an image and dump it on the drive. > 2. Figure out some way to get the first sector after the last ISO from the > disk, and start writing the new data there. (I checked camtools and readcd > and came up with nothing.) > 3. Make a new ISO with all of the old and the new data, write that out to > disk. (A bit resource intense, but it should work.) > > > The question for you is whether I was thorough enough evaluating method 2. Is > there some way to find out the last sector used on a SCSI device from the > command line? If not, is there some way to roll my own? Check out the -C and -M options for mkisofs. Also, you don't need to use readcd to write the image. You can just use dd. e.g.: dd if=image.iso of=/dev/cd0c bs=2k (you can use seek= to jump forward on the disk, so you don't have to start from the beginning each time) Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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