Partition falied Input/Output Error

I have got the very same problem, USB 2.0 250GB external drive, that worked perfectly under Windows XP. I tried to format two partitions, one FAT32 and one HFS+ for Time Machine.

XP can still format the drive but Leopard gives me a "Partition failed Inout/Output Error".
Maybe somebody can help us?

Some other people said they needed to get WD LifeGuard utility and run it in XP to disable a "security feature" I believe to get theirs to work. And that WD is looking and working on what to do to be more Mac compatible.

I use to see a mix of messages about WD MyBook Pro and the Mac Pro and some having issues with these devices a year ago when the Mac Pro came out. Now, seems there is a Leopard related issue.

Past OS X releases often required firmware updates to LaCie and Oxford 911-based cases. We all remember the 10.3.0 fiasco with FW devices. But 10.4 also unless it was relatively new case.

If you can use another interface (some have 3-4 interfaces, FW800 and eSATA as well as USB/FW400) try that.

Hey!
I got the same problem with my Pleiades with an 160 GB Samsung IDE Drive. Same with another disk (Samsung 120GB). The disks are not broken or something else, Linux and also Windows were able to partition the disk. After 2 days of googling I found a very helpful tip at apfeltalk.de! A user had the same problem like we, he tried to create a HFS partition with Windows, for this you need the tool "MacDrive 7" which can create HFS+ partitions with Windows.

I tried also this way, and whooooooaaaa it works!!! 🙂
So my conclusion is that OS X got problems when it was "talking" to the USB Controller. I read that a lot of them are not using the "real" USB Standard. Developers try only with Windows and that works also if it is only "near the standard"...

It seems it is just a conflict of Leopard with the USB-Chip of the drive. I tried it using a Firewire 400 connection and it worked without any problems. I guess it should work with your drives, too.

I get the input/output error message with a firewire drive. The workaround is to load the Tiger install DVD and format from there.

Definitely a bug.

The plot thickens:

I bought a NeweTech miniStack v2 (500 GB) to use for backing up my Intel Mac mini. I also have a LaCie mini Hard Drive and hub (see, so it all looks pretty when stacked up).

I setup Time Machine, and while my Powerbook finished backing up through AFP (wireless), the mini was abysmally slow. Elsewhere in this forums I saw the recommendation to reformat usign GUID Partition Table (drive came with the older Apple Partition Map scheme.

As described above, I got the Input/Output Error. Tried doing it from the Tiger installer CD that came with the computer (not the same as the retail DVD - that one does not support Intel macs). Disk Utility just sat there with the spinning beach ball of death instead of the immediate error.

So I tried something else: I plugged in the miniStack to my Powerbook G4 running Leopard. From there, Disk Utility successfully formatted the drive! So it's probably not a Leopard Disk Utility bug, at least not on PowerPC computers.

One other thing that could be the issue: The drive was connected to my mac like this:
Mac mini -> LaCie mini HD -> miniStack v2.
(Firewire).
What if the problem is in the LaCie's FW hub or if Mac OS has some trouble with the daisy chained drives? In the meantime, I reconnected like this:
Mac mini -> miniStack v2 -> LaCie mini HD.

We'll see if Time Machine behaves nicely now.

Yes, it's definitely a bug. When using Tiger it is possible to format/partition the mobile external drive. Using Leopard Disk Utility reports I/O error.

Did anybody filed a bug at ADC already?

i had the same problem. I tried formating on my windows machine as Fat32 but still had same problem. Then I downloaded free trial of Macdrive7 and formated the drive HFS. still had same error the I discovered by "Get Info" that the drive was not capable of being Journaled so I tried extended mac (in disk utility Leopard) and it worked.

Yesterday I installed Leopard. Everything works fine. But after two or tree ours of use, Time Machine start working and then the machine freeze. Ive rebbot and after that my external drive not mount anymore.
Ive try to format the external drive and receive the famous "Input/Output Error" and can't format the drive.
I think this it's a problem whit the mac or the USB or a bug and no a drive error.
This night I try to format on a WIndows machine and on an old eMac whit 10.4

The drive is an Maxtor 6 L250 Gb. IDE - Case USB 2.0

If anyone can solve this "Input/Output Error" problem, please share here.
Thank's!

(Sorry for my english)

Im here again with good news!
I can succefully format my external hard drive. The trick was made via the 10.4 original instaler disk!
In my case the "Input/Output Error" is a bug on 10.5

Now my external disk it´s working.

I'm running 10.4.11 and I'm having a similar issue with my Western Digital 500 GB external via USB. I had successfully partitioned the drive, however when copying files to it there is a input/output error and all the contents of the destination folder disappear, yet the files are still there once I plug it back in.

Would trying to reformat in Windows using Macdrive7 maybe help? I hope an update comes out to fix this by either WD or Apple.

Ive got the same exact issue. Just wanted to keep this topic alive.

Anyone have any success?

Well I just tried to partition my external drive using Tiger on my old G4, and it didn't work for me. It made two partitions totalling about half the 400Gb disk and then gave up. I tried it several times, using all the available types of formatting, but without any change in the result.

My hard drive enclosure used to hold a 250Gb HDD, sold originally as an external drive by Iomega. Could the chipset in the case be limiting it to 250Gb, perhaps? The full size of the new 400Gb HDD shows up on the desktop OK before I attempt to partition

I fixed the problem.

I opened Parallels and formated and repartitioned the drive in windows.

Then I went to diskutility and erased the drive and formated to HFS+

Then Time machine was able to discover the drive and work.

Hope this helps someone.

Tom