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Brit Ben · Jan 10, 2002, 04:53 PM

I have a CD format DMG file, all set up as an apple bootable CD. I need to convert the DMG file to an ISO or IMG file to burn from a PC workstation.

Any one know the weird incantation of hdiutil ??

Thanks,
Ben.

philzilla · Jan 10, 2002, 05:04 PM

as far as i know, it won't work. two words: resource fork. you can store the raw files on the pc, but the second they get burned to cd, they's fux0r3d. can't tell you why, because i don't know that much about it. i just know it happens. hang around a while and someone should fill in the blanks. i'd be interested to know the full reason myself

el_humpo · Jan 10, 2002, 05:18 PM

If you convert the Mac image (HFS filesystem) to an ISO (ISO 9660 filesystem) then it will not be bootable - Macs must boot off of a HFS or HFS+ disk (or UFS in the case of OS X).

The only PC program that can burn HFS discs (AFAIK) is Nero Burning Rom - http://www.nero.com/, and it is severely limited. If you attach a SCSI hard disk with an HFS filesystem on it to your PC, Nero will burn it to a CD. It won't read Mac disk image files.

I think you're out of luck here; unless you beg, buy, borrow or steal a burner for your Mac

starman · Jan 10, 2002, 05:20 PM

Or...burn the DMG file to a CD-RW, and take it someone who DOES have a burner on their Mac.

Mike

philzilla · Jan 10, 2002, 05:45 PM

Originally posted by starman:
Or...burn the DMG file to a CD-RW, and take it someone who DOES have a burner on their Mac.

if you're going to do this though, stuff the file first, or you'll just hit the same problem. .sit files can survive on a pc-burned cd, but that's all. once it's on whoever's mac, unstuff it then burn. you should be sorted then

Brit Ben · Jan 10, 2002, 05:56 PM

Originally posted by philzilla:


if you're going to do this though, stuff the file first, or you'll just hit the same problem. .sit files can survive on a pc-burned cd, but that's all. once it's on whoever's mac, unstuff it then burn. you should be sorted then

Hmm, Okay, All advice appreciated so far, except.....

I *know* that this is possible, because I have done it before.
After the 10.1 update was announced, I burnt 5G64 from a DMG
file to a CD, using a PC cd burner.

Heres the thing:

1) Resource forks.

These won't be touched by the PC, since the PC will not tamper with any contents inside a RAW image file.

2) Bootable disk

Same thing. As long as all the boot information is correctly in place inside the DMG file (it is) then when the utility converts the DMG to a raw disc file, the eventual disc will be bootable.

Perhaps I should have worded the question better. How do I translate or convert a DMG to a RAW image file.

I'm fairly sure it is an hdiutil command, but I can't find the thread in the archive anywhere !

Cheers,
Ben.

Xeo · Jan 10, 2002, 06:53 PM

Have you read the man page for "hdiutil"? I don't know exactly how to do it, but I'm guessing this is part of it.
<BLOCKQUOTE>code:<HR><pre> convert imagefile -format format -o outfile [options]

convert imagefile to type format and write the result to outfile.

The correct filename extension will be added only if it isn't
part of the provided name. Format is one of:

UDRW UDIF read/write image
UFBI UDIF entire image with MD5 checksum
UDRO UDIF read/only image
UDCO UDIF ADC-compressed image
UDRo UDIF read/only (obsolete format)
UDCo UDIF compressed (obsolete format)
UDTO DVD/CD-R master image
UDxx UDIF stub image
UDZO UDIF zlib-compressed image
RdWr NDIF read/write image (deprecated)
Rdxx NDIF read/only image (deprecated, but
still usable on OS 9 and OS X)
ROCo NDIF compressed image (deprecated)
Rken NDIF compressed (obsolete format)
DC42 Disk Copy 4.2 image

and options are any of:

-align sector_alignment

default is 4 (2K)
-pmap add partition map.
When converting a NDIF to a any variety of UDIF, or
when converting a partition-less UDIF to UDIF, the
default is true.
-segmentSize [sector_count]
Specify segmentation of imagename into sector_count-
sized segments. The default sector_count when
-segmentSize is specified is 2*1024*1024 (1 GB seg-
ments) for UDTO images and 4*1024*1024 (2 GB seg-
ments) for all other image types.
-shadow [shadowfile]
provide a shadow file to be used in conjunction with
the base image as the image source. The default
shadow file name is imagename.shadow.
-tasks task_count
When converting an image into a compressed format,
specify the number of processors to use for the com-
pression operation. The default is the number of
processors active in the current system.[/code]

CharlesS · Jan 10, 2002, 08:44 PM

Re: Macs not being able to boot from ISO 9660 CD-ROM's - this is just not true. I know for a fact that Mac OS 9 can boot from an ISO 9660 CD-ROM. Not sure if X is different, but I have no idea why it should be.

The problem is, a lot of disk image formats only store a partition. DMG files store an image of the entire device, including all the partitions, and you need to have a lot of hidden partitions to hold the CD drivers and other necessary stuff for a boot disc. So before you try converting to a format, make sure that format supports multiple partitions first. I don't think that the .img images do, for example (although I may be wrong).

[ 01-10-2002: Message edited by: CharlesS ]

Brit Ben · Jan 14, 2002, 01:32 PM

Originally posted by CharlesS:
Re: Macs not being able to boot from ISO 9660 CD-ROM's - this is just not true. I know for a fact that Mac OS 9 can boot from an ISO 9660 CD-ROM. Not sure if X is different, but I have no idea why it should be.

The problem is, a lot of disk image formats only store a partition. DMG files store an image of the entire device, including all the partitions, and you need to have a lot of hidden partitions to hold the CD drivers and other necessary stuff for a boot disc. So before you try converting to a format, make sure that format supports multiple partitions first. I don't think that the .img images do, for example (although I may be wrong).

[ 01-10-2002: Message edited by: CharlesS ]

Of course it isn't true. ISO is the *standard* for how data is laid on a CD at a lower layer than the filesystem.

a DMG storing multiple partitions, is by default, a correctly formatted ISO image. you simply ftp the DMG file *using binary mode* to the PC, rename the extension to a .iso and fire up the burner software. As long as you tell WinonCD or EasyCD or whatever, that you wish to burn a disc from an image, you'll be fine.

The burner software doesn't care about the contents of the image file, so resource forks, HFS and 'bootability' for want of a better description will all remain intact as long as you have a valid, mountable DMG file.

No end of pain and suffering for this obvious solution.

Cheers,
Ben.

Brit Ben · Jan 14, 2002, 01:36 PM

Originally posted by Xeo:
Have you read the man page for "hdiutil"? I don't know exactly how to do it, but I'm guessing this is part of it.
<BLOCKQUOTE>
UDTO DVD/CD-R master image
</BLOCKQUOTE>

Xeo, helpful and correct as always.

hdiutil convert OSX.dmg -format UDTO -o OSX.img

I didn't need this because I created the disk image as a CD format to begin with.

Cheers,
Ben.

Carnage Visors · Jan 14, 2002, 08:34 PM

What I do with this, is convert the image using disk copy, to a cd/dvd
master, rename it with a .iso extension and use nero to burn it with no
issues.

Benjamin