Date: Thu, 03 Jun 1999 18:11:14 -0500 From: David Kelly <dkelly@hiwaay.net> To: Kiril Mitev <kiril@ideaglobal.com> Cc: mph@astro.caltech.edu (Matthew Hunt), freebsd-questions@FreeBSD.ORG Subject: Re: how to make an ISO image of a CD ? Message-ID: <199906032311.SAA24517@nospam.hiwaay.net> In-Reply-To: Message from Kiril Mitev <kiril@ideaglobal.com> of "Thu, 03 Jun 1999 19:08:20 BST." <199906031808.TAA07664@ideaglobal.com>
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Kiril Mitev writes: > > You shouldn't need anything special. I can make an image from my > > SCSI drive with: > > > > $ dd if=/dev/rcd0c of=image.iso bs=2048 > > > > You should substitute /dev/rwcd0c since you have an IDE drive, I > > suppose. Without the "bs=2048" I get errors due to the blocks read > > being shorter than the CD-ROM's sector size. > > Thanks, but will it have all relevant ISO header stuff & such as well ? If the original is a single session CD, then the above will work. But might barf exactly two blocks before the end. In prior employment I spent a lot of time making image dupes of CDs. Most I had mastered myself. Too many to keep the mkisofs image laying around for future use. So I had (now lost) a script which used "cdrecord" in its querry mode to tell me how many sessions and how many blocks were on the CDROM. I subtracted 2 from the reported block count. Then used this count with dd to read the image from the CDROM. Irix and FreeBSD handle raw SCSI errors differently. Am not sure how important it is to skip the last two runout blocks under FreeBSD. Found if I didn't skip them, each generation my CD grew by two blocks as cdrecord adds two more. System was an SGI O2 with Irix 6.3. A built in CDROM. Plus an external CD-R. Irix wouldn't mount the CD-R but cdrecord had no problems writting. So after I read my image from the internal CD. I launched cdrecord writting to the CD-R. At the same time I used "find" to walk the CD filesystem generating md5 sums for every file. When that finished the script kicked out the original. When the CD-R was finished writting, it was ejected too. Then the operator was instructed to place the copy in the internal CD. Then my script started verifying the files using md5. A fancy version of the script would start writting another copy while the prior was being verified. Couldn't find anything in Irix like FreeBSD's vnode, so there was no way to mount the CD image file as we can with FreeBSD. -- David Kelly N4HHE, dkelly@nospam.hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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