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External USB Disk Drive Won't Mount

B

BadboyHouse

macrumors 6502
Original poster
Nov 1, 2011
261
1
Hi all. I've purchased a 500GB portable external disk drive for my MacBook Pro so that I can use TimeMachine for backups.

I connected the drive to my crappy old XP netbook and formatted it as FAT32 (it was NTFS out of the box).

The problem I've got is that the MacBook won't see the drive when it's connected. The drive light come's on and it definitely powers up, but it doesn't show anywhere - not in the Finder or in the Disk Utility.

On the XP netbook it works fine and files can be copied to and from it without any problems.

Any advice on what I can try next?

Thanks in advance
 
FAT32 will not work with Time Machine.

____________________________________________________________

Overview of the four major file systems (called "Formats" in Mac OS X) used on Windows and Mac OS X, compiled by GGJstudios. You can use Disk Utility to format any HDD to your liking.

Any external hard drive will work with PCs or Macs, as long as the connectors are there (Firewire, USB, etc.) It doesn't matter how the drive is formatted out of the box, since you can re-format any way you like. Formatting can be done with the Mac OS X Disk Utility, found in the /Applications/Utilities folder. Here are your formatting options:

FAT32 (File Allocation Table)
  • Read/Write FAT32 from both native Windows and native Mac OS X.
    [*]Maximum file size: 4GB.
  • Maximum volume size: 2TB
  • You can use this format if you share the drive between Mac OS X and Windows computers and have no files larger than 4GB.
NTFS (Windows NT File System)
  • Read/Write NTFS from native Windows.
  • Read only NTFS from native Mac OS X
    [*]To Read/Write/Format NTFS from Mac OS X, here are some alternatives:
    • For Mac OS X 10.4 or later (32 or 64-bit), install Paragon (approx $20) (Best Choice for Lion)
    • For 32-bit Mac OS X, install NTFS-3G for Mac OS X (free) (does not work in 64-bit mode)
    • For 64-bit Snow Leopard, read this: MacFUSE for 64-bit Snow Leopard
    • Some have reported problems using Tuxera (approx $36).
    • Native NTFS support can be enabled in Snow Leopard and Lion, but is not advisable, due to instability.
  • AirPort Extreme (802.11n) and Time Capsule do not support NTFS
  • Maximum file size: 16 TB
  • Maximum volume size: 256TB
  • You can use this format if you routinely share a drive with multiple Windows systems.
HFS+ (Hierarchical File System, a.k.a. Mac OS Extended (Journaled) Don't use case-sensitive)
  • Read/Write HFS+ from native Mac OS X
  • Required for Time Machine or Carbon Copy Cloner or SuperDuper! backups of Mac internal hard drive.
    [*]To Read/Write HFS+ from Windows, Install MacDrive
    [*]To Read HFS+ (but not Write) from Windows, Install HFSExplorer
  • Maximum file size: 8EiB
  • Maximum volume size: 8EiB
  • You can use this format if you only use the drive with Mac OS X, or use it for backups of your Mac OS X internal drive, or if you only share it with one Windows PC (with MacDrive installed on the PC)
exFAT (FAT64)
  • Supported in Mac OS X only in 10.6.5 or later.
  • Not all Windows versions support exFAT. See disadvantages.
  • exFAT (Extended File Allocation Table)
  • AirPort Extreme (802.11n) and Time Capsule do not support exFAT
  • Maximum file size: 16 EiB
  • Maximum volume size: 64 ZiB
  • You can use this format if it is supported by all computers with which you intend to share the drive. See "disadvantages" for details.
____________________________________________________________
​

To have an OS independent HDD, use Disk Utility to format it with exFAT, but this will also not work with Time Machine.
 
I know that FAT32 won't work with Time Machine.

I understood that in order for OSX to "see" the external drive it would need to be formatted as FAT32. Once I can get OSX to see the drive I will format it as a proper mac drive.

Problem is OSX won't even see the drive.

It's 500GB - do this matter?
 
BadboyHouse said:
I know that FAT32 won't work with Time Machine.

I understood that in order for OSX to "see" the external drive it would need to be formatted as FAT32. Once I can get OSX to see the drive I will format it as a proper mac drive.

Problem is OSX won't even see the drive.

It's 500GB - do this matter?
Click to expand...

In order for Mac OS X to see the drive, it does not need to be formatted at all, as Mac OS X can format empty drives or already pre-formatted HDDs just like Windows, at least in my experience.

Have you tried an SMC reset yet?
Intel-based Macs: Resetting the System Management Controller (SMC)
It helped me getting to recognise some stubborn external HDDs.
 
Tried resetting no difference.

I was expecting OSX to just pick the drive up and let me format it.
 
BadboyHouse said:
that link is dead.

I was expecting OSX to just pick the drive up and let me format it.
Click to expand...

That link works for me, but the Apple Support pages seem to be a bit funky the last weeks.
If that link still does not work, try this link, it is a PDF I created of that page.

And normally OS X can pick up external HDDs, but sometimes even that gets funky. Or it is the HDD and its USB controller. Thus the SMC Reset tip, as it helped me.
 
I've done the reset - this made no difference.

To confirm what I've tried now:

1. Plugged drive in straight after taking out of the packaging (NTFS formatted)
2. Formatted in Windows as FAT32
3. Reset SMC

Still the drive won't mount, and does not show up in Disk Utility.
 
BadboyHouse said:
I've done the reset - this made no difference.

To confirm what I've tried now:

1. Plugged drive in straight after taking out of the packaging (NTFS formatted)
2. Formatted in Windows as FAT32
3. Reset SMC

Still the drive won't mount, and does not show up in Disk Utility.
Click to expand...

That is not normal.
Tried another USB port yet?
Can you link to the HDD, so we can see, what model you got?
And which Windows version and way did you use to format the HDD?

Do you hear the HDD spin up after connecting it to the MBP?
 
I am not knowledgable enough to know, if it might be a USB 3.0 issue, but I guess not.

Can you use Control Panel > Administrative Tools > Computer Management > Disk Management to format the HDD to exFAT, if you have Windows XP SP3 or higher?
 
I doubt it can be a usb 3 issue as it works on my xp netbook which is usb 2.

Tried formatting as exFAT - this makes no difference.

The drive powers up etc but nothing shows up in osx disk until or finder.

I can see me having to return the drive to the shop for a refund. :(

Seems crazy though that a simple usb drive won't work.
 
BadboyHouse said:
Seems crazy though that a simple usb drive won't work.
Click to expand...

I agree, but sometimes "simple" also means cheap, and the USB 3.0 controller can't be properly recognised. Though I never bought a USB 3.0 device, as I stick to USB 2.0, FW800 or eSATA for data transfer, and haven't had such problems yet (and I bought/have fifteen external HDDs and some other bare HDDs lying around).
 
Yes it's obviously not compatible. Still I'm really shocked that it will work on an old XP netbook but not the latest MacBook.

If I buy a different drive, how can I be certain that it will work?
 
BadboyHouse said:
Yes it's obviously not compatible. Still I'm really shocked that it will work on an old XP netbook but not the latest MacBook.

If I buy a different drive, how can I be certain that it will work?
Click to expand...

If a Mac OS X logo is on it.
But I also bought many "cheap" USB 2.0 portable HDDs, where no Mac OS X compatibility was listed on the box, and none ever gave me headaches. It maybe the USB 3.0 chipset in the HDD with the actual problem.
 
I just got back from the store. The tech/sales guy's eyes almost popped out of his head when I said it wouldn't work. He couldn't believe it.

Anyways, I will most likely get a drive from eBay. There are plenty of sellers on there who list their drives as osc lion compatible.

Thanks for all your help!
 
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