Can't perform "Duplicate" backups to DVD - Why?

[robertades]

Retrospect Professional 7 won't allow duplicate backups to DVD for some reason and I don't know why.

 

I use the program to backup my Adobe Photoshop files, but want to be able to see the files w/o have utilize restore. I also noticed that when I do a Normal backup of Photoshop files, the files are not compressed, even though compression is selected from within the program. Therefore, I see no reason NOT to use Duplicate, although the program won't permit it.

 

Why?

[natew]

Hi

 

Duplicate is not designed to work with DVD. You might be able to force Retrospect to duplicate to a DVD RW disc but I don't believe we support that.

 

Thanks

Nate

[robertades]

This brings up three follow-up questions:

 

1. With respect "Duplicate" backups, why does Dantz differntiate between a DVD/CD media and other types of backup?

 

2. With normal backups of Photoshop or digital "raw" files why does the program fail to compress them when the user so requests?

 

3. Why after normal backups to a DVD, is the DVD unreadable? That is, Windows cannot determine the quantity or the date of the data on a Retrospect DVD, why?

[natew]

Hi

 

Duplicate is designed to be used with hard disks and network volumes. Duplicate is designed to update, add or delete files on the destination media. You can't do that with +R or -R formats.

 

You could certainly duplicate to a DVD-RAM disc if you wanted to. That will work just fine.

 

Backups made in Retrospect are made in Retrospects own data format. This is required to provide true multi-session writing to the disc and to support point in time restores.

 

Retrospect automatically skips compression on file types that cannot be compressed well. Just out of curiosity, how much compression do you get on a raw photoshop file with Winzip or some other utility.

 

Thanks

Nate