Time Machine: Airport/USB drive or File Server?

[space-time]

I have some older Macs backing up with time machine to a USB hard drive attached to an Airport Extreme Base Station. I have some newer Macs backing up to a Mac Mini File Server.

One difference I see that that via Airport/USB, they back up to a disk image, and when using the server, they back up to files and folder (no disk image involved).

Moving forward, I need to make some upgrades. Is there a good reason to choose one of the other? which method is more reliable?

[kj4btkljv]

Just curious... is the Mac Mini running OSX Server?

On my OSX Server, running a Time Machine backup destination, I get the disk images from all of my workstations.

Jeff

[space-time]

Yes, 10.6.8 server but I think it backs up to files and folders, I don't think there is a disk image. I back up to an external drive attached to mini. I will check tomorrow to confirm that I have files and folders on that drive.

On the airport disk I do have disk images, one for each computer.

EDIT:

I just checked: the mini itself back up the the external hard drive to files and folders.
The MacBookPro backs up to the same external drive (via File Sharing) to a disk image. So I was wrong last night.

[deckeda]

I created my own sparsedisk images and then copied them to the USB drive hanging off my 5th gen AirPort Extreme. I can still use it as a local file server if I want. For each Mac, Time Machine mounts the disk and then unmounts it when done, just like if everything was a Time Capsule.

And if I need to copy the backups to another drive, it's as easy as using the Finder to drag the sparsedisk image, something you can't do with a tethered ™ Backups.backupdb folder.

Actually, even if all I had was a tethered USB drive (not a network drive) I'd still setup TM that way for those reasons ... also means other users don't accidentally futz with an always-mounted TM drive.

http://code.stephenmorley.org/articles/t...ork-drive/

The instructions above work for anything 10.6 or later, but for me didn't become rock solid until 10.7 or 10.8 ... it's not the "unsupported" router that was the issue.