[plug] FireWire Hard Drive Question

[Craig Ringer]

James Devenish wrote:

> You are correct that although the FireWire drive itself would be
> portable, the partition tables and filesystems are the defining factors
> for compatibility. If you are able to format the drive using a PC-style
> partition table, then all of Mac/Windows/Linux should be able to read
> it <-- this was a dubiously-educated guess, hopefully someone else will
> set the record straight.

If it's dubiously educated, that's not obvious from the fact that it's 
100% correct (even for MacOS 9, though it sometimes took some convincing 
to get it to see PC partition tables - I think you have to do something 
with File Exchange or some add-on).

> The initial choices for filesystems that come to mind are HFS+, ext2/3,
> UFS, NTFS, FAT32 (or whatever it is that Windows uses).
> 
> I know that Linux read and write HFS (Mac) partitions, but you might not
> have the same luck with HFS+.

HFS+ is now also supported under Linux 2.6, though I seem to recall that 
HFS may be broken to some extent. I've never had particularly good 
results using HFS CD-ROMs, but I can't speak for HFS disk filesystems or 
HFS+ volumes of any sort as I've hardly used them on Linux.

Be aware that working with HFS/HFS+ volumes under OSes that don't 
understand resource forks can be a bit ... "interesting". Doing the 
wrong thing can result in corrupted files.

> If you can't use HFS+, then you will
> probably lose UNIX permissions :-( The advantage of HFS+ is that it is
> the best bet for giving you the "best of both worlds" with Mac and
> Linux.

I think you can also access HFS (I don't know about HFS+) with various 
3rd party utilities for Windows, though I'm not aware of a filesystem 
driver for HFS/HFS+ under Windows (except ancient ones for floppies). I 
seem to recall a "file browser" like application that could access HFS 
partition and uncompressed disk images.

> Alternatively, if you can find read/write Mac OS X kernel modules for
> ext2/ext3, then I suggest that you chose this path. This will give you
> 'UNIX' but not so much 'Mac'.

On the Windows side, you won't find it hard to find ext2/ext3 file 
browsers either. Again, I don't know if there is a real filesystem 
driver (Windows _does_ support them, they're just apparently a screaming 
nightmare to write).

Current Linux UFS support appears to be read-only :-(

If all you want to do is store collections of files (using the disk for 
transferring things around), I'd probably go for FAT32. MacOS X will 
handle its lack of resource fork support by creating ._$FILENAME files 
to store the resource data, so you'll be able to store data that 
requires resource forks on the disk. Be aware that OS/X does _NOT_ store 
the finder info (as the NetATalk people are eternally cursing them for) 
on the disk, so you can run into interesting problems with aliases and 
running applications from the disk.

Windows and Linux won't care about the Mac resource fork data - you'll 
just see lots of "._$FILENAME" files under Windows (they'll be hidden by 
default on Linux). You will need to remember to move the resource file 
with the data fork file if you ever move mac files around though. This 
problem is one you'll suffer with pretty much any filesystem except 
HFS/HFS+ so it's probably not worth worrying about.

--
Craig Ringer