How Do I Format USB Flash Drive in MAC OS Ext
 

Hello,

As you know, most every USB flash drive you purchase these days comes pre-formatted in FAT or FAT32. I have one connected to the USB port of my iMac (333mhz, 96mb RAM) that I want to initialize to MAC OS Extended. However, when I try to format it, the only option I have is DOS format. Drive Setup in OS 9 is of no help either, and I do not have access to an OSX box.

Is there some third-party software out there that I can use to accomplish this?

I know I cannot be the only person who has attempted this...

Any help would be much appreciated. Thanks.


In a world without walls and fences, who needs Windows and Gates?

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

why do u need to format - doesnt it work with fat too?

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

Otherwise known as FAT.

There may be a way to format it with a third party tool, but as proliant_fan said, why? One of the biggest drawbacks to formatting a portable device in HFS is that it is no longer compatible with Windows -- you must reformat it back to FAT for it to be readable on Windows. Furthermore, Mac OS X has complete support for FAT, so your USB drive will be multi-platform (Linux also supports FAT natively).

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

First, thank you for your replies to my post.

Second, I figured out a way to do it - so simple that when I realized it, the sound of my palm hitting my forhead could be heard in the next town. I just disabled File Exchange, rebooted, then the OS told me it was unreadable and offered to format it for me (which I did).

Lastly, to respond to your questions of "why?", the answer is simply this: I am not concerned about cross-platform file exchange with this USB drive. It stays in my iMac from startup to shutdown for use as as a backup drive for important files so I don't have to change out 100MB Zip disks. From a data intregrity standpoint, I just feel better knowing that my FileMaker files are stored in a native Mac format rather than PC-DOS. I would have no reason to move these to a PC, and if I want PC files on my Mac, I will just use one of my other USB drives to do that.

I currently use two XP Pro boxes, an Ubuntu Linux box, and even an old Win98SE box occasionally for some older apps that I use once in a while. But with my Mac, it's more - well, philosophical I suppose. My Mac is a Mac, not a PC, and I don't want a FAT-formatted disk in there. Might not make sense, but that's the long and short of it.

Cheers.


In a world without walls and fences, who needs Windows and Gates?

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

I had a problem with two San Disk USB flash drives. They were loaded with software for Windows, useless for mac OS 10.4.8. Once I had dumped the software I noticed that the drives were formatted in MS-DOS. I reformatted them in MAC OS Extended using "Disk Utility". They didn't work in MAC OS Extended, causing freezes before a file had been copied or after. Upon reading the "joeprogrammer" solution in this post, I reformatted both drives in MS-DOS and sure enough the drives work fine. When working with large Photoshop files (100+MB), the drives like to be connected directly to the USB2 port on the back of my Intel iMac and will misbehave if connected to the USB2 powered hub. I am also "pro" mac, but sometimes we have to live with Windows solutions. It could be possible that the San Disk USB flash drives are not MAC OS Extended or Standard friendly.

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

I have been noticing some amazing things, at least to me.

I format the SanDisk Ultra II in many different ways on my mac. They all tell me the capacity of the 2GB unit is:

960.7 MB (1,007,378,432 Bytes)
Available is: 945.4 MB ( Used is 15.3 MB) and I haven't done anything but erase it!!!!

Now, if I open a terminal window and do a df I get

Filesystem 512-blocks Used Avail Capacity Mounted on
/dev/disk1s3 1967536 31288 1936248 2% /Volumes/Movies
xanadu:/Volumes woo$ ls -al Movies
total 0
drwxr-xr-x 4 woo woo 170 Jul 23 23:16 .
drwxrwxrwt 6 root admin 204 Jul 23 23:16 ..
drw------- 6 woo woo 204 Jul 23 23:16 .Spotlight-V100
d-wx-wx-wt 3 woo woo 102 Jul 23 23:16 .Trashes
xanadu:/Volumes woo$


1) How many bytes will this thing actually hold. The terminal says 1,963,248 which I find reasonable for a 2GB drive. The disk utility says 945 MB or so. That's what the finder also says is available if you click on the drive.

Why this discrepancy? How does it take 15 MB to put a couple of folders on the drive? Is that part of the directory structure?

BTW, Once I format it any mac or unix, the Windoze formatting isn't an option any longer. How would I format it back to Windoze if I wished?

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

The thing holds 960.7 MB. 15 MB are already used.

Wrong. That's the number of blocks. On this device, a block is 512 bytes, so when you do the math, it works out to 945.4 MB, which is exactly what the Finder reported.

I wish I knew the exact reason, but that's actually pretty normal. Just about every filesystem I make already has about 15 MB or so used after I format it.

I'd do it with the terminal. Open it up from /Applications/Utilities/Terminal. First, you need to find the device name, so enter this:

mount

Look for /Volumes/NameOfUSBDrive. To the left of it should be /dev/something, that is the name of your USB device. Now format the drive, substituting usbdevice with the name of the device:

newfs_msdos -F 32 /dev/usbdevice

Re: How Do I Format USB Flash Drive in MAC OS Ext
 

something to do with wasted chunks. i remember it used to be a hot topic in the days of win95 (fat16 was not efficient, you could lose like 10% of your drive)

also flash memory is never the exact size

e.g my 64mb pda is 62mb, my 512mb sd is 487 and my 4gb stick is 3.9