backing up to a windows server & data integrity?

[coldspella]

have a windows 2000 server network with Mac connecting to it. I am having problems getting my Veritas software to read the Mac for backup purposes and getting retrospect to backup the Mac workstation so I want to Copy the Mac hard drive to a share on the server and than do the backup.

 

I will be copying the Mac hard drive to the servers using Retrospect. They claim that I will lose Mac specific information if I copy the files to the server. We have not had this problem with any other files that we have shared back and forth so I was wondering if anyone has experience with this? If so, have you had any problems with the files if a restore was necessary? Any help on this will be appreciated.

 

Thanks

Cathryn

 

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[wkegel]

There are two major issues when moving files from a Mac to a Windows environment: resource forks and file system details.

 

Traditionally, A Mac file can consist of two parts: a data fork and a resource fork, each of which can be empty. An standard JPG file has just a data fork, while an Mac OS9 program usually has only a resource fork. If you copy files over to a Windows file system, the datafork ends up as a normal Windows file, and the resource fork is either ignored or saved in auxiliary files - depending on what you use for copying. Even if the resoource fork is saved, it's a rather fragile construct - the connection between the two parts can easly get lost.

 

The most obvious example of filesystem details are filenames: both environments have different rules. The differences are much less problematic than 15 years ago, but they still exist. The file transfer software usually handles that by slightly altering filenames if necessary. Less visbile but sometimes just as important are file attributes and file ownership. On a Mac, since it's build on top of a Unix system, each file has an owner and atrributes which determine what the owner, people in the same group and the rest of the world can do with it: read it, write to it and/or execute it. On a Windows system, the location of the file usually determines what you can do with it: if it's in your directory it is yours. And then there are things like aliases on a Mac which are similar to shortcuts on a Windows system - but they are definitely not the same thing. Backup programs like Retrospect are aware of all these details and preserve all that information as part of the backup. File transfer programs don't.

 

Whether your stragegy will work depends thus very much on what you are trying to do. Is your idea to copy the files to the Windows server and than backup the copy? That will definitely not work for a complete disk, but it may work if you are just looking for a way to backup data files like images and Office documents. Most applications on a Mac do not create resource forks, and altering file names and ownership usually isn't that much of an issue.

However, Retrospect is an exception: a Macintosh file Backup and a catalog do have both a a resource and a datafork. The resource fork is small, and contains mostly icons and similar stuff - I'm not sure how important that is. So if you plan to use Retrospect to do a File backup on the Mac and then transfer that Retrospect file to your Windows server, you may run into problems. It will also be rather inefficient: each time you add some files to your Retrospect backup, the backup file changes and it will be backed up up on your Windows system - you'll do the equivalent of a full backup every time.

 

Frankly, I would advise you to avoid issues like this and try to get your network backup to run - it's bound to be much more efficient and much more reliable.

 

Greetings,

Wim Kegel