Multisession DVD-R

Question

Level 1

10 points

Multisession DVD-R

Hi all,

Can anyone give me a good reason WHY OS X doesn't support this? Windoze has had this ability for almost a decade. I've found lots of posts asking if there's a way to do it, and so far the answers are:

1. No.
2. Yes, but only CD-R, CD-RW, DVD-RW
3. Media's cheap. Just waste the discspace.
4. Program XXXX can do it. (but in reality it can't)

Anyone?

Thanks,
SyddyS

Mac Pro 2x3.0 Dual, Mac OS X (10.4.9)

Posted on May 21, 2008 2:41 PM

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Answer 1

Kappy

Level 10

361,741 points

May 21, 2008 3:17 PM in response to syddys

To burn to a recordable CD so you can burn to it again:

1. In Disk Utility, create a disk image that contains the files you want to burn to the disc.

The files must be from a volume with a Mac OS Extended disk format. To check a volume’s disk format, select the disk in Disk Utility, and look at the information at the bottom of the Disk Utility window.

2. Select the disk image in the Disk Utility list, and then choose Images > Burn.

3. Select the “Leave disc appendable” checkbox. If you don’t see this option, click the triangle in the top-right corner.

4. Insert a blank recordable CD in the optical drive and click Burn.

To add more files to the disc later, follow the steps above. You can continue this process until all available space on the disc is used.

I do not have a DVD-R with which to check if this will work properly, but it does work on CD-R media.

CD-RW and DVD-RW media must be erased before re-written, but multisession writing should work as well.

There are several third-party utilities as well:

Burn Again
Burn Again DVD
Toast Titanium
DiscBlaze
BurnX Free

You'll find them at VersionTracker or MacUpdate.

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Answer 2

deh2k

Level 4

1,871 points

May 21, 2008 4:49 PM in response to syddys

My understanding is this: DVD-Rs were designed for video DVD compatibility, and as such, the official specification does not support multiple sessions. Some vendors have workarounds for it, but the results are problematic. So Apple decided not to provide multiple sessions at all rather than provide an unreliable feature.

Multiple sessions on DVD+R media may be supported, but I have not tried it.

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Answer 3

syddys Author

Level 1

10 points

May 22, 2008 8:51 AM in response to deh2k

Well, that's as close to an answer as I've gotten, so thanks for that! Of course, my comeback would be that CDs were originally designed for audio 🙂

I've been using multisession DVD-R in Windoze for years using Nero, and have never had a problem. They read/write just fine (and even work through Nero in Parallels!). It's a great way of making backups of projects without filling your office with a single DVD per project. Just keep adding to your "2008 Projects" DVD until it's full, then start "2008 Projects 2".

Blaming reliability just doesn't fly with me, sorry. Ah, well. Sounds more like, "Well, we haven't bothered so far, so why bother now? Wouldn't you rather have Cover Flow or a partially transparent menu bar?"

Any further explanation from the hardcore would be much appreciated!

Thanks,
SyddyS

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Answer 4

syddys Author

Level 1

10 points

May 22, 2008 8:55 AM in response to syddys

Oh yeah, sorry I forgot to address Kappy- sorry folks, multisession DVD-R is not supported through Disk Utility or any of the software listed there. It's like it's "locked out" at the OS level. Otherwise, you'd think one of the 3rd party vendors like Roxio would have figured it out.

-SyddyS

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Answer 5

deh2k

Level 4

1,871 points

May 23, 2008 10:38 AM in response to syddys

syddys wrote:
Well, that's as close to an answer as I've gotten, so thanks for that! Of course, my comeback would be that CDs were originally designed for audio 🙂

Sure, though my comeback to you would be that there are specifications for various data formats on CD-R but none for multisession DVD-R.

Your comment about coverflow and menu bars is irrelevant.

What's wrong with getting DVD+R media instead?

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Answer 6

syddys Author

Level 1

10 points

May 23, 2008 2:05 PM in response to deh2k

deh2k wrote:
Your comment about coverflow and menu bars is irrelevant.

What's wrong with getting DVD+R media instead?

I'm sorry, I didn't mean to dare question the motives of the Almighty Apple, even jokingly. Back to business, everyone.

Multisession DVD+R is also not supported, but thanks I actually hadn't thought of that.

Just found this in a Toast forum (from a Roxio tech): "'There's no multi-session DVD burning. It's not readable by the Mac OS even if you found an application that lets you do it...No, Toast doesn't burn multi-session DVDs either because the Mac OS won't mount the multiple sessions."

Oh well. That seems to confirm it. It's unfortunate- that's a handy feature.

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Answer 7

Király

Level 6

10,017 points

May 23, 2008 2:12 PM in response to syddys

There is no widely accepted standard for multisessions DVD-Rs. Any that exist are proprietary to individual developers and are likely not supported by any other app. I think it's for this reason that Apple chooses not support it in OS X.

Retrospect is one such Apple app that supports multisession DVD-Rs. I use this feature myself. I have used Retrospect to write and append 20+ backup sessions to the same DVD-R media.

But the format Retrospect uses is proprietary to Retrospect only, and only Retrospect can read the multisession discs. Mac OS X cannot read them at all.

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Answer 8

WWJD

Level 6

15,830 points

May 23, 2008 2:32 PM in response to syddys

I use Burn Again DVD and it works with DVD-RW discs. The OS can read the discs without special drivers, etc..

Regards,

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