Mac os unable to format external drive

I am unable to reformat Seagate Free Agent Pro external drive used for Time Machine backup. Disk Utility gives error msg; "Couldn't unmount disk." I attempt to initialize an identical external drive and receive the same message. Any ideas?

Drive Erase for Lion/Mountain Lion
1. Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button. Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select the volume you wish to erase from the left side list. Click on the Erase tab in the DU main window.
3. Set the format type to Mac OS Extended (Journaled.) Click on the Erase button and wait until the process has completed.

Similar Messages

Unable to format external drive as Mac OS Extended

I just bought a WD 3TB My Book Essential external hard drive so I can free-up space on my Mac Mini. When I used Disk Utility to erase the data and reformat the drive as Mac OS Extended, I got the following error:
+Disk Insertion+
+The disk you inserted was not readable by this computer+
There were three options; Initialize, Ignore or Eject. Choosing either Initialize or Ignore resulted in the following error:
+Disk Utility Internal Error+
+Disk Utility has lost its connection with the Disk Management Tool and cannot continue. Please quit and relaunch Disk Utility+
So I Googled it and found the following thread http://discussions.info.apple.com/message.jspa?messageID=11461203
This suggested using First Aid; Repair Disk. When I ran this, I got the following error:
+First Aid failed+
+Disk Utility stopped repairing “disk4s1” because the following error was encountered:+
+Filesystem verify or repair failed+
I'm stuck; does anyone have any ideas how to resolve this?!

Not sure what the problem was on the MacMini (10.5.8), but I just managed to format the disk on my MacBook Pro (10.6.4).
Problem solved!

Transfer files from Mac formatted external drive to PC formatted drive

i need to transfer quicktime files (that were captured from video with FCP) to a PC formatted external drive (for editing them in after effects on a PC). the files can be transfered by burning them on a DVD, but that will take a very long time and waste many DVDs because i have 60 GB of material... can this be done (without having to purchase expensive software)?

thanx tom,
first of, i like that you made the link appear as one word. how did you do that? it's really cool!
i downloaded the program, but i'm not sure how to use it... reading the guide just made me more confused... if i understand correctly, it will automatically reformat ALL my files to NTFS-3G ones, which are not as stable... i'm a little scared to install it... though i may have totally misunderstood what it says. i see mostly black when i try to read these kind of things...
anyone out there have experience with this program?

Unable to unlock external drive or repair (but can change password)

I have a Freecom 1TB USB 2 external drive with a single partition with Filevault 2 encryption enabled.
The Mac Air detects the drive and prompts for the password to unlock. Prior to this problem it was retrieved automatically from my Keychain (entry still there). An incorrect password immediately gives the window shake. The correct password results in either a prompt to re-enter a password after few minutes or considerably longer.
Disk Utility (run from a standard or admin account or in recovery mode) appears to Verify and Repair the drive fine, but when the partition is selected I get:
Verifying volume “1,000”
Checking storage systemChecking volume.
disk3: Scan for Volume Headers
Invalid Volume Header @ 0: incorrect block type
Invalid Volume Header @ 999709908480: incorrect block type
disk3 is not a CoreStorage volume
Error: Storage system verify or repair failed.
The Repair option is not available.
Earlier I was getting an "Unable to examine /dev/disk3: Resource busy" message on Verifying the partition.
Earlier I also got a message in the details of drive Verify or Repair in Recovery mode of "transaction group 12: cksum mismatch", though the final result of the Verify and Repair stated the drive was okay.
Oddly I seem to be able to change the password, but nothing else including switching off encryption. When the later is attempted it appears to accept the password but then stops stating there was a problem (no other details).
I have a second external drive with Filevault2 enabled and this connects fine although a password is prompted for even though I saved it to my Keychain previously.
Suggestions very welcome! Preferrably to fix or if that is not possible ways to potentially retrieve some of the data.
Drive and Partition info from Disk Utility:
Name : Freecom Mobile Drive XXS Media
          Type :           Disk
          Partition Map Scheme :           GUID Partition Table
          Disk Identifier :           disk2
          Media Name :           Freecom Mobile Drive XXS Media
          Media Type :           Generic
          Connection Bus :           USB
          USB Serial Number :           C0001E86AA51
          Device Tree :           IODeviceTree:/PCI0@0/EHC2@1A,7
          Writable :           Yes
          Ejectable :           Yes
          Location :           External
          Total Capacity :           1 TB (1,000,204,886,016 Bytes)
          Disk Number :           2
          Partition Number :           0
          S.M.A.R.T. Status :           Not Supported
Name : 1,000
          Type :           Encrypted Logical Partition
          Disk Identifier :           disk3
          Mount Point :           Not mounted
          Disk Status :           Online
          File System :           Mac OS Extended (Journaled, Encrypted)
          Connection Bus :           USB
          Device Tree :           IODeviceTree:/PCI0@0/EHC2@1A,7
          Writable :           Yes
          Universal Unique Identifier :           7663BACA-6B14-3D7F-8C39-5A5319AE9F4B
          Capacity :           999.71 GB (999,709,908,992 Bytes)
          Owners Enabled :           No
          Can Turn Owners Off :           Yes
          Can Be Formatted :           Yes
          Bootable :           Yes
          Supports Journaling :           Yes
          Journaled :           No
          Disk Number :           3
          Partition Number :           0

I'll answer my own question, which may help others.
I found no solution and reformatted the drive.
Not sure if my question was poorly worded but after no response I tried one of the main paid support sites. The expert who took up my question didn't seem at first to be aware of encrypting external drives under Lion. No viable solution was found, so I gave up and reformatted the drives.
This is the third time I have had issues with the stability of OSX formatted external drives, so enough is enough. I'm sticking with FAT32 (the 4Gb limit isn't a major problem) for all my drives except my Time Machine drive. No encryption on that drive either.

How can i clone a copy of Mac OS X to an external drive?

Hi Yesterday the guys at the apple store had to reinstall my OS and they installed OS X 10.6 is there a way to create a copy of this to an external hard drive to use in the future if i need to boot from an external source?
Cheers
matt

First, you need to do this:
Repairing the Hard Drive and Permissions
Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer. Now restart normally.
If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.
Second, clone your drive to a freshly formatted external drive.
Clone using Restore Option of Disk Utility
1. Open Disk Utility from the Utilities folder.
2. Select the destination volume from the left side list.
3. Click on the Erase tab in the DU main window. Set the format type to Mac OS Extended (journaled, if available) and click on the Erase button. This step can be skipped if the destination has already been freshly erased.
4. Click on the Restore tab in the DU main window.
5. Select the destination volume from the left side list and drag it to the Destination entry field.
6. Select the source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.
Destination means the external drive.
Source means the internal startup drive.
Now, you can use other cloning software but the most reliable and easiest method is what I've described above.

How to access an ex fat formatted external drive on OS 10.6.8

How do I access an ex fat formatted external drive on OS 10.6.8 ? Drive has audio files and was originally formatted and created by a Windows PC.
When the La Cie drive is plugged in to my mac mini, it says can not recognize formatting.

Read this thread
exFAT mounting problem

Format external drive partition under 10.2.8

Hello. I have been trying to setup a WD My Book 500gb with 2 partitions to be used as on offsite backup unit for our business computers. We have one Mac (this G5), and 4 Windows stations (3 XP/ 1 98SE). I am trying to setup this unit with one partition using NTFS and the other with Mac HFS or HFS+ file systems. I have found a utility that allows me to format the partition that I intend to use with the Mac as a FAT32 partition. I then tried bringing the WD MyBook to the G5 and reformatting that partition as HFS. When I run Disk Utility, I click on the partition showing as Fat32 under disk2 and then click on the Erase tab, select Mac OS X Extended file system, no OS9 drivers, have tried various names (Mac BU, My Mac BU, My MacBook, etc), then click Erase, Confirm Erase. The progress bar comes up for a moment or so, says that it is erasing the volume, then exits out as if done. Unfortunately, it never mounts the drive and the volume no longer shows up in Disk Utility (only shows the Drive without any recognized partitions) until I close and restart Disk Utility. When I restart Disk Utility, the volume I am trying to format once again shows up under the drive, tho now with no name. Under Identification, it says Mount Point: Not Mounted/ Format: MS-DOS/ Capacity: 116.44gb. After doing some browsing around onthe internet trying to troubleshoot this on my own, I found some reference to Disk Utility logs (supposedly avail in upper right corner, tho didn't find there). I searched in the Library/Logs/Crash Reporter and found 'Disk Utility.crash.log' which says:
Date/Time: 2008-09-17 21:25:42 -0400
OS Version: 10.2.8 (Build 6S90)
Host: Joanns-Computer.local.
Command: Disk Utility
PID: 540
Exception: EXCBADACCESS (0x0001)
Codes: KERNPROTECTIONFAILURE (0x0002) at 0x01215088
Any suggestions on how I might get this partition formatted for a Mac file system? I would use Fat32, but I plan to use RSyncX to backup this G5 and would like to make the backup bootable in case of critical failure. And since I am using this drive as a backup storage device rather than file sharing system, I have no need to access files on either partition from the opposite operating system.
Thanks in advance for any help that can be rendered. Also, if more info or more of the log file is needed to diagnose, please let me know.
PS: Sorry if this is in wrong forum. Wasn't sure if this falls under Setup, Customizing or something else.

You can either format the drive entirely FAT32 that can be used on both Windows and Mac or you can format the drive entirely for the Mac, but you cannot have one partition of each on the same drive (not with Jaguar. You would need Leopard to accomplish that and an Intel Mac.)
There is this article/hint explaining a method for doing so, but I do not know if it is doable with Jaguar. Maybe Panther since the hint appeared about the time Panther was released.

Does Mac OS firewall also protect external drive connected to iBook?

Hi all,
I have an iBook G4 to which I've connected an iomega external firewire drive divided into two partitions (a clone of my iBook, plus a section used for photo storage).
I have the firewall turn ON in my iBook's system preferences, and none of the sharing options are enabled.
I'm wondering if this firewall will also protect my external drive?
I'm connected (authorised user) to the internet via airport coming from a network set up by my landlord, who lives downstairs.
I'm wondering if it's OK to leave the ext. drive plugged in all the time (if it's protected by the firewall), or should I unplug it when not in use?
Anyone know?
Thanks

The external hard disk drive is accessed via your computer,
so the only way an external off-site attack could be performed
would be through the System; it has the Firewall, if turned on.
Unless the external hard disk drive is of the type or configured
to be accessed remotely or through some wireless setup to
share it via a base station or other device for backups or other
uses, it should be as safe as the hard drive in the Mac. But, if
the external drive is on an unsecure wireless network for shared
use, then the settings of the wireless base station should be set
and when not present, if no shared use is expected or desired,
an external unit could be unmounted from the desktop & powered
off until the next time it is needed.
So, under normal wire-connected use, an external drive should be
protected and as secure as the System itself; with some exception.
It is possible to change settings inside the computer and allow
other users or persons with access, to get into a computer remotely.
If you do not have these possibilities open, they can't gain access.
Hopefully this helps...
Good luck & happy computing!

Suddenly Mac mini won't "see" external drives. Possible related to OS software update to 10.6.8?

Suddenly Mac mini won't "see" external drives, neither Firewire nor USB. Possible related to OS software update to 10.6.8? Worked fine under 10.6.4. Any advice? Thanks.

Turns out it was nothing to do with the OS update, it was just a loose cable plug connecting my FireWire/USB hub to the computer. But your tip is a good one -- I'd been wondering why the external drives (even when mounted properly) weren't showing up in the sidebar. Thanks!

How to format external drive for mac AND pc use

hi
i want to format my external drive so i can use it on my mac and on pc's as well. i've gathered that the MS-DOS format is the way to go. my question is this: would this create any problems for my mac then?
can i partion one part for ms-dos and part for macos extended?
cheers
-j-

There are a couple of disadvantages with formatting a
disk as FAT32. Firstly, there is a limit on the file
size for FAT32. I think it like 2 GB so if you
capturing video the results will probably not fit
into this file limit. Secondly FAT32 will not be
bootable. I alway clone my system to a backup disk as
bootable. That way if anything goes wrong with my
system, I can just boot from my backup disk and fix
it.
The problem with doing this though is that the drive will not be usable with Windows (which was in the original posting) unless you use the third party MacDrive software on the PC.
iFelix

Format external drive for Mac and PC?

Can I format an external Drive to have 1 partition for OS X and another for my wife to use with her PC?
thanks!
ray

Yes, just use Disk Utility under OS X to create two volumes on it, one Mac OS Ext, the other FAT. Use a Master Boot Record partition scheme (also known as “fdisk”).

Error code -36 when copying to Mac formatted external drive

I'm trying to move my iPhoto library to an external drive to save space on my iMac's hard drive. It starts to copy it fine but after a few minutes stops with the error "The Finder can’t complete the operation because some data in “iPhoto Library” can’t be read or written. (Error code -36)"
The external drive is an iomega minimax and is formatted as "Mac OS extended (journaled)". I'm running Mac OS 10.6.3 and the iPhoto Library is for iPhoto '08 version 7.1.5.
Help! Thanks.

Kids birthday party today - sorry about the delay in replying.
This is an interesting problem, if disk integrity and space are not the problem.
My next step would be to use the command line to copy the library to your external disk. To do this, open Terminal and type:
cp -R ~/Pictures/iPhoto\ Library /volumes/yourextenaldiskname/Pictures/
Note that, if you have any spaces in your external disk name, you will need to put a backslash in front of the spaces.
Let me know how it goes.
Cheers,
Rodney

Format External Drive - From Mac for Windows

I have a Maxtor One-touch that I need to back up a bunch of data for a Windows XP user. After some research, I thought that formatting the drive in the MS-DOS (FAT) format would do it, however, after doing so and moving all of the data, I have tried the Harddrive on a PC running Windows XP. The drive doesn't mount.
The external drive is a PC/MAC compatible version. Am I overlooking anything? Is there something I need to do in windows to access the drive.... because it's not obvious.

Hi Christopher,
follow either Templetons advise or (if not possible) use Disk Utility and set the partition scheme (behind the Options button) to MBR (Master Boot Record) and use MS-DOS (= FAT32) as file system.
That should also do the trick.
The 'standard' partition scheme on Intel Macs is GPT (GUID Partition Table) which can sometimes lead to the effect with Windows PC that you observed.
Hope it helps
Stefan

Can't format external drive for Mac

I got an external Seagate Freeagent 750GB drive to use with my new Mini. It came formatted as a windows FAT volume. Since I don't have a FW400 to FW 800 cable yet, I have it connected via USB. When I try to reformat as a Mac drive (with any of the 4 case-sensitive / journaled options), I get an error, but I can then reformat as FAT. Does anyone know how I can format this drive as mac and what the problem is?

It may have something to do with the partition scheme. There are at least three different schemes. One is used for windows formats (so you can use FAT32 or NTFS format), one is used for Intel Mac (probably GUID, not sure), and one is used for PowerPC Mac (probably the Apple Partition Map, again not sure). I don't know whether it is smart enough to choose the appropriate scheme for you when you have selected a format for your partition. Try to select the right scheme for Intel Mac first, and then decide on the format on each (if you have more than one partition on that disk) partitions.
I think you have to make sure the format is compatible with the scheme, especially when you have multiple partitions on one disk. You can't format one partition to FAT32 and another to HFS+, although it will try to do something, but it will end up with error.

How to format external drive for use against windows and mac

Hi.
Please bear with me, a possible MAC newbie here
I'm about to buy the 13" Mac Book Pro (after ditching the Lenovo X301 because of a super slow processor, slow FSB, slow intel graphics).
But I have a couple of questions before I buy this Mac Book Pro.
NOTE:
My main OS (stationary pc) is Windows, and will probably be so for a long time.
But I need a lightweight laptop while on the run, and could not actually find any other one than the Mac Book Pro that met my requirements.
I'm using Adobe Lightroom for indexing and managing images on my windows stationary computer and will also use Lightroom on my Mac Book Pro.
I'm to use an external HDD for this purpose and will need to be able to both write and read to/from that HDD from both MAC and Windows.
Export lightroom library to External HDD from Windows (thumbnails + keywords).
Import new images and edit keywords etc from mac book pro in lightroom.
Import changes into my windows library version after been edited from library in mac book pro.
What options do I have when it comes to formatting that HDD?
What will the PROS and CONS be for the different options?
Note (I'm not to switch to Aperture (my main computer is still Windows))
Regards

Hi.. and thanks for that answer... another related here:
I'm to buy this external drive:
http://www.lacie.com/no/products/product.htm?pid=11038
This page:
http://pc.wikia.com/wiki/FAT32
tells me that windows XP will only format FAT32 to max 32GB,
will my upcoming MAC book PRO be able to format that whole disk using FAT32?
Or do I have to use something else to format it with?
Regards

Mac os unable to format external drive

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