Indexed files on other file systems formats: maintaining DT3 attributes

I’m thinking about setting up a shared hard disk so that I can access indexed files (not the databases or imported files) from both my Mac and from Linux and/or one of the BSDs.

The shared disk will hang off the back of the router so that it will be permanently available, even when the Mac laptop (where the databases are housed) is off – otherwise I’d just ssh in.

Does anyone have any experience with this?

My reading suggests that the only real candidate for sharing between Mac / Linux / BSD systems is Exfat, but that this loses some permission and attribute data.

Ignoring the security aspects, does this have any effect on how DT3 deals with the files: I.e. does it lose valuable DT3 specific data?

I don’t really understand the ins and outs of file systems and their attributes, so please forgive the naivety of the question…and any other comments/suggestions are very welcome!


You should be fine with indexed files. I just checked here, and even with an imported file, DT does not use the macOS’ file system’s extended attributes to store for example tags. So, apparently DT’s metadata are separate from the file system ones.

Something else, though: If, as you’re saying, the disk is attached to your router (presumably using USB-C or something like that), your choice of file systems is limited by your router’s capabilities. The OSs you were mentioning shouldn’t have a play in that since they will be accessing this disk using a network file system like (most probably) SMB/CIFS.

Such a network file system introduces just another level of abstraction and allows you to access your data from different operating systems. Having said that, there are probably better choices than ExFAT as a file system for a hard disk. But again: If your router only supports ExFAT, you have to go with that. An alternative, depending on your ability and interest to spend money, would be a NAS (networked attached storage). Those usually provide more functions (and more security), are a tad faster than a disk attached to your router, and employ more advanced file systems. They, of course, allow you to access your data using a network file system.

A note of caution: Do not put your DT databases on a drive connected as a network file system unless you have a stable (at least) Gigabit line to it.

Also, if you ever feel fancy and add tags or other extended attributes to network files from your Mac, you might face some trouble: Which file systems and Cloud services preserve extended attributes? – The Eclectic Light Company


Thanks very much for such a comprehensive reply!

Previously, I had an iMac which was permanently on, so I didn’t need to worry about the complications of a shared drive. I either used Syncthing or SSH, but that’s not useful with two laptops.

The basic idea was to use Chronosync to keep a couple of relevant folders on the Mac and the external drive in sync, and so they’ll be available from the {Free/Open}BSD laptop without having to turn the Mac laptop on.

I’ve got a spare 3TB disk lying round, so I’ll use that, but there would have been no point if the DT3 info was lost, and your answer has helped a lot. Thanks!