Portable Hard Drives: Linux and Mac

Factual Questions
1

Hi there,

I’m purchasing a portable hard drive as a christmas present for my brother and I’m wondering about compatibility issues.

Most of the portable hard drives I’ve taken a look at do not mention Linux, and I have no experience with that particular OS whatsoever, so I’m not sure if there are ever any compatibility issues with it.

What it will be used for is backing up a PS3 in order to install Linux onto it (or something along those lines) and also for carrying around large amounts of raw music data for various Macs.

Would most that say they work with Mac OS work with the PS3/Linux too?

2

Any modern USB hard drive will be compatible with both Linux and Mac, but the recipient will need to format the drive to give it a suitable file system.

Most USB drives as shipped are either formatted FAT32 or NTFS. FAT32 is usable from Linux, OS X(Mac), and Windows, but cannot handle large files. NTFS formatted drives can be used from Linux (with caveats) and Windows, but I am not sure if OS X supports it.

Anyhow, the disk can be formatted easily enough to suit.

Si

3

NTFS is supported on a read-only basis by MacOS X right out of the box; to turn on the ability to write to those drives you need to install MacFUSE and the NTFS-G extension. Works fine in my limited experience: save existing files with modifications, copy files from local drive to the NTFS drive, delete files, rename files, create folders, delete folders, move files into or out of folders, etc etc.

4

HFS+ (aka HFS Extended), the modern Mac-native format, is also supported on the other two platforms with appropriate add-ons. I think the popular one for Windows is called MacDrive.

I don’t spend much time in Linux builds but I understand that the drivers do exist:

So that’s a second modern/robust format that all 3 platforms can use.

Finally I think there is extfs support on both Windows and MacOS. (That would be the Linux-native file system, yes?). I can’t tell you much about the solidity of the Mac drivers, and nothing at all about the Windows variant.

5

A subject that I have very recently become familiar with :slight_smile:

As noted, any modern USB drive should work fine, at a hardware level, with Mac OS X and Linux. The format is the only issue.

Out of the box, OS X 10.5 (Leopard) and Linux have read-only access to NTFS. All should be good if all you want to do is read files from the external drive on either platform.

If you want to write files, you need to use additional drivers.
In my configuration (Mac OS X), I needed to read/write NTFS, so I looked at two options:
[ul][li]Use a utility called MacFUSE witha driver called NTFS-3g[/li][li]Use a commercial product from Paragon software.[/ul][/li]I opted for the commercial product since it is supposed to be faster, it definitely is easier to install, and it should be supported by them.
It’s a bit pricy at 39.95.

One can always reformat the new drive as HFS+ for Mac or ext3 for Linux, but then you have a similar problem trying to write to the partition from Windows.

Of course, one may ask “Why not just use FAT32”?

The main reason folks go to other file systems is file size: FAT32 cannot handle the huge files one generates when dealing with video.

My reason was a little bit more technical: I am using rsync to create my backups, and I discovered that the timestamp of FAT32 files cannot be before 1980 and has a resolution of two seconds.
I have some scanned photos from 1977, which I gave an exif date of 1977 and a file timestamp to match. When I do a backup, these constantly got copied over since the target drive always turned the 1977 to 1980.
The time resolution is a tricky issue. Since my machine’s file system has timestamp resolution of 1 second, whenever there was a timestamp of an odd second, it would be rounded to the nearest even second on FAT32, and rsync would treat the files as different and recopy tons of stuff. There is a command line switch in rsync to avoid this, but why bother? Why not use a better file system (NTFS)?

I reformatted to NTFS from a Windows machine and am now test driving the Paragon NTFS drivers for Mac. Seems to be working like a charm!
My first backup is complete.

6

I didn’t know about that Paragon product.

7

It was my understanding last time I tried that Windows doesn’t support all the ext3 extensions and treats an ext3 drive as an ext2 drive (which is ok, as 3 is backwards compatible).

The real question is what the PS3 uses. Windows, Linux, and Mac are far more configurable.

eta: that is to say, add-on drivers for Windows.

8

This is not always reliable and results in file system consistency checks when booting back into Linux. I gave up using this tool. The Windows ext2/3 reader from sysinternals is good, and I have used that for read-only access several times.

Si

9

Good to know, thanks.

10

This CNET article says you need to use FAT32 for backing up the PS3. It’s not clear from that what format it uses on itself, but I don’t know how much that matters if you’re putting Linux on it.

11

Found it on Amazon for $26, direct from Paragon, and ordered it with free shipping.

Glad I’m still in my trial period and I didn’t buy it from the Paragon site. Man that chafes me when vendors sell their stuff for so much more on their own site. If it was from Joe’s Computer Shop having a sale, I would let it slide, but this one is directly from Paragon, fulfilled by Amazon.

(back on topic) Anyway, I think FAT32 may be your only option, as a lowest common denominator.

12

Ahh, thankyou for the very helpful replies.

After reading a bit more, I had begun to figure that Linux could handle any hardware I threw at it. I’ll also forward the formatting information to my brother.

13

ext2 and ext3 are the major filesystems currently in use under Linux, yes. (The difference is that ext3 is a journalling filesystem, meaning it’s more robust in the face of sudden shutdowns and doesn’t need to be checked as thoroughly. As mentioned above, ext3 filesystems can be treated as ext2 filesystems with some caveats.) There are many others, all of which could be described as ‘native’.