Reformat a single partion on an external USB drive?

I have 4 partitions on an external drive, 3 are used to back up various files, the 4th I left as a 200 gig partion in case I need it for storage. Now however, I would like to reclaim some of that Leftover space and partition it into GUID so that I can create a bootable Lion Install Drive for recovery purposes. Is this possible or would I need to reformat the entire drive (which I don't want to do)? Thanks

Within Disk Utility, just click on the partition you want to format. There actually isn't a way to format multiple partitions at once, so only the partition you select will be impacted. Just be sure you select the right partition!

Similar Messages

Single-user mode: How to mount and access an external USB drive?

My MacBook Pro HD is acting up. Cannot boot normally or into "safe mode". Cannot reinstall OS without wiping out the HD. Need to recover some critical files but DiskUtil First Aid and Restore options cannot successfully complete. Problem traced down to "invalid node structure" which means I either have a hardware problem or my filesystem partition directory structure is corrupted. I need to recover some files that are not backed up (timin issue with my regular backup process).
I can boot into single-user mode, mount the root file system (/sbin/mount -uw /) and can see/navigate the rot filesystem structure via good UNIX command line. Here's what I would like to do (in single-user mode):
1. Mount an external USB drive (250 GB already formatted as Mac OS X Extended)
2. Copy various files and/or directories from my HD to the external USB drive (UNIX cp command)
I realize I could go spend $$ for the Disk Warrior or Data Rescue products (or something similar) that SHOULD help me recover my HD or files, but it seems silly to do this when I can see, touch and taste them from within single-user mode....
Comments? Suggestions?
TIA --
Trent
P.S. Once I've recovered my files, I'll try to reformat the HD and then reinstall the OS. And THEN go have Apple look at my machine (thank goodness for AppleCare coverage)!

Resolution:
1) Boot system in single-user mode (SUM) with external HD attached.
2) Execute the following UNIX CLI commands once SUM boot process is completed:
# fsck -fy
# mount -uw /
# mkdir /Volumes/target_directory
# mount -t hfs -w /dev/diskXXX /Volumes/target_directory
# cp -RXv /source_directory /Volumes/target_directory
Where XXX is the device-level name for your external HD's data partition. In my case this was /dev/disk1s2. It may take some experimentation to identify this device name if your system has multiple HD's.
3) Verify contents were successfully copied onto the /Volumes/target_directory.
Comments and observations:
- Do NOT use "/" as your source directory - cp will make a second (redundant) copy of /volumes/target_directory
- I was able to successfully copy ALL files off my HD despite the fsck command's "invalid node structure" error message with this simple procedure. YMMV, depending on the state of your HD.
- The repeated disk0s2: I/O error warnings displayed during the SUM boot process did not seem to have a negative effect on this procedure. I also received this same error warning intermittently as I navigated the mounted filesystem did not seem to be a problem, either. Again, YMMV.
Commercial software:
I downloaded ProSoft Engineering's Data Rescue 3 product (trial version) before spending $99 to attempt to recover my "bad" HD's data via mounting to a good system with FW target mode. It could not successfully complete its "QuickScan" process and immediately hung on block 0 of 390M during its "Deep Scan" process. The product did seem to function properly on an operational system. ProSoft's technical support was responsive and helpful but had no answer for my "Deep Scan" error.
I did not attempt to use Alsoft's Disk Warrior 4 product. I could not find any trial software available and was reluctant to spend $100 based upon the mixed reviews and comments on this discussion forum as well as other reviews. Alsoft does claim to address the "invalid node structure" error in their marketing materials. Hindsight being 20/20 - I saved $100 by using this simple procedure.
Final note:
Neither Leopard nor Snow Leopard's installation DVD could recognize the bad internal HD when trying to do a reinstall. While DiskUtil was able to "see" the bad internal drive it immediately failed when I tried to do an "erase and format". Took the system to my local Apple store and the Genius ran a tool called "SMART Utility" from Volitans Software (www.volitans-software.com). SMART utility confirmed that my HD was bad so it was replaced. AppleCare pays for itself (once again!).

External USB drives slow

Hi,
I recently purchased 2 Seagate Freeagent 500gb. I was copying files from my old external to the new one and it was going to take a ridiculously long time. So I checked into it and found the drives were showing up on the "USB Bus" in System Profiler and not the "USB High Speed Bus". This brought the speed to 12MB/s instead of 480MB/s.
Big difference. I played around with it, ejected all the drives then plugged in the Seagate's first and they went to the the High Speed Bus.
The problem is as soon as I restart they go back to the slow 12MB/s bus. I then have to eject them, and load them 1 by 1.
What gives? Anybody have any ideas?

The following fix -- partitioning the external USB drive twice using the correct partition scheme -- fixed this problem for me.
I can't claim originality -- I got the idea from a Time Machine thread on apple.com (which I can't find now).
Unplugging the external USB drive and cycling power was not working for me -- so there may be more than one problem here.
Here's what worked (note that this will erase the disk!):
1 - Open Disk Utility and highlight the disk description (not the volume name).
2 - Choose the "Partition" tab (which won't appear if you have the volume highlighted).
3 - In the Volume Scheme pull-down, select "2" (or any other number 1).
4 - Click the Options button and choose the GUID Partition Table (if you've got an Intel Mac -- other choices are explained on the page that appears).
5 - Click "Apply."
6 - Now repeat steps 3 - 5, except create a single partition (Volume Scheme = 1).
That should do it!
While you've got Disk Utility open, you may want to check your drive format as well.
(cross-posted in http://discussions.apple.com/thread.jspa?messageID=6050391#6050391 )

External USB drives will not mount under Mountain Lion

Since upgrading to Mountain Lion, two external USB2 drives that I have will not mount and cannot be viewed in the Finder. The same occurs on a 2012 MacBook Air, a 2009 iMac 27 and a 2010 MacMini, all running OS X Mountain Lion version 10.8.2.
Both drives are Samsung Story external USB drives (one is 1.5 GB and the other is 2 GB) and both have been formatted using Mac Disk Utility with a single Mac OS Extended (Journaled) partition, one using Snow Leopard and the other with Lion.
Both still mount correctly on a friends MacBook Pro that is still running Snow Leopard, and I had no problem with the same drives under Lion. Interestingly both can also be connected to Time Capsule USB port and show up correctly.
Both drives mount correctly under Windows 7 on BootCamp partitions that I have on both the 2012 MacBook Air, a 2009 iMac 27. These BootCamp partitions have Paragon HFS+ installed so I can read Mac formated drives.
Both drives show up in Disk Utility, but when attempt to mount the drives I get the message "The disk could not be mounted. Try running First Aid on the disk and retry mounting." I can run Repair in First Aid on the disk and get the message that the volume appears OK, but again have the same problem when I attempt to mount the disk.
I have also tried using Disk Utility 3,2, but still cannot mount the drives, though the program indicates there is no problem with the drives.
I have other portable USB including a Samsung portable USB2 drive, and two external USB3 drives, and I don't have problems with them.
There is clearly a problem with Mountain Lion with accessing (mounting) these Samsung Story USB drives, and the problem appears to be with Mountain Lion itself as the problem did not occur on the same Macs with Lion and does not occur with Bootcamp partitions on the machines.
I have a lot of time searching forums, but I have not found anyone with an identical problem.
I sure hope someone can help or that Apple come up with a fix for this issue which has only developed since the update to Mountain Lion.

bj10au wrote:
Since upgrading to Mountain Lion, two external USB2 drives that I have will not mount and cannot be viewed in the Finder. The same occurs on a 2012 MacBook Air, a 2009 iMac 27 and a 2010 MacMini, all running OS X Mountain Lion version 10.8.2.
Both drives are Samsung Story external USB drives (one is 1.5 GB and the other is 2 GB) and both have been formatted using Mac Disk Utility with a single Mac OS Extended (Journaled) partition, one using Snow Leopard and the other with Lion.
Both still mount correctly on a friends MacBook Pro that is still running Snow Leopard, and I had no problem with the same drives under Lion. Interestingly both can also be connected to Time Capsule USB port and show up correctly.
Both drives mount correctly under Windows 7 on BootCamp partitions that I have on both the 2012 MacBook Air, a 2009 iMac 27. These BootCamp partitions have Paragon HFS+ installed so I can read Mac formated drives.
Both drives show up in Disk Utility, but when attempt to mount the drives I get the message "The disk could not be mounted. Try running First Aid on the disk and retry mounting." I can run Repair in First Aid on the disk and get the message that the volume appears OK, but again have the same problem when I attempt to mount the disk.
I have also tried using Disk Utility 3,2, but still cannot mount the drives, though the program indicates there is no problem with the drives.
I have other portable USB including a Samsung portable USB2 drive, and two external USB3 drives, and I don't have problems with them.
There is clearly a problem with Mountain Lion with accessing (mounting) these Samsung Story USB drives, and the problem appears to be with Mountain Lion itself as the problem did not occur on the same Macs with Lion and does not occur with Bootcamp partitions on the machines.
I have a lot of time searching forums, but I have not found anyone with an identical problem.
I sure hope someone can help or that Apple come up with a fix for this issue which has only developed since the update to Mountain Lion.
You can start here
http://support.seagate.com/kbimg/flash/213059/213059_EN.HTML
Pete

Unable to access external USB drive on my windows machine

I have an XP SP2 box with several partitions. I Just purchased a MacMini (fisrt time apple user). I have joined the maac to the same workgroup as the XP box and can access all the partitions on the XP box with no problem. With the exception of the C: drive and the External USB drive.
I have the drive at Fat32 and can connect directly to the mac with no problems. Read, write all works fine. connect back to the XP box and I get an error -43. It ask for a user name and password and knows if I use the wrong password. I can even see a list of shares on the sub folders of the external drive but get the error when I try to access.
Thanks in advance
Mac mini Mac OS X (10.4.4)

This could be a smart design inside XP. FAT32 can't store file ownership so maybe it refuses to share a FAT format drve? From a security point of view this would be the right thing to do. On the other hand it could be a bug in XP that just by dumb lock looks like it is doing the right thing.
Either way it sounds like you have a good workaround: put the drive on the Mac and let the Mac share the drive. It's best if the drive is reformatted for the Mac so that user ownership and permissons can be used.
Don't worry one computer can't know how another's dive is formatted. The network hides this. All my shared files are on EXT3 formatted drives on a Linux server. All the clients see is "SBM".

Disk Utility Not Formatting External USB Drive

Hello,
I recently upgraded to Leopard.  Around this same time, my company purchased two, 1 Terabyte USB External drives for my coworker and I in the graphics/web development department.  They arrived this morning and we were very excited.
My problem is that I cannot get Disk Utility to erase/format the new, external USB TB drive for use with my MBP.  Disk Utility fails almost immediately with the following message:
"*Disk Erase Failed*
Disk Erase failed with the error:
File system formatter failed."
The options I'm choosing for the Erase are:
Volume Format: MAC OS EXTENDED  (i've even tried the 'journaled' version too)
Name: TB
As soon as I hit 'Erase' I get the error message I listed above.  The volume never mounts on my desktop and does not exist.  I can see the drive itself in the System Profiler, so my Mac sees it, it just can't format it!  I've also made sure all my permissions were repaired, so I'm just a little confused as to why this simple task keeps failing?
Is there some additional, esoteric step that I'm missing?
My coworker was able to get his disk to work because he did NOT have Time Machine turned on yet.  When he connected his new TB drive, Time Machine asked him to format/initialize the disk and he of course said "ok."  I had Time Machine set to use my OLD external USB drive and it's been working great. As of this writing, my coworker is a happy camper. I, however, am not.  I'm not blaming Time Machine, just noting the differences between my coworker's experience and my own. Since the volume is not currently mounted on my machine, I can't format my disk the same way as my coworker has done using Time Machine, since Time Machine doesn't see the volume.
My fear is that the manufacturer (whom I've also contacted and am awaiting their response) will throw this back to a software problem....and the folks on the forum here will point their fingers and say 'hardware problem.'  Ah, the eternal struggle.....who to blame?
Any help or additional troubleshooting tips are greatly appreciated.

This is the best, and only, way to format an external hard drive, which is courtesy of Kappy.
Extended Hard Drive Preparation
1. Open Disk Utility in your Utilities folder. If you need to reformat your startup volume, then you must 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 Installer menu (Utilities menu for Tiger or Leopard.)
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Click on the Options button, set the partition scheme to GUID (only required for Intel Macs) then click on the OK button. Set the number of partitions from the dropdown menu (use 1 partition unless you wish to make more.) Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the volume(s) mount on the Desktop.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process will take 30 minutes to an hour or more depending upon the drive size.
Steps 4-6 are optional but should be used on a drive that has never been formatted before, if the format type is not Mac OS Extended, if the partition scheme has been changed, or if a different operating system (not OS X) has been installed on the drive.

PowerBook G4 external USB drive problem

I've got a 12" Powerbook G4.
All of the following operations were performed with the laptop plugged into the power adapter.
Today I connected a Bytecc external USB drive model 7050 containing a Maxtor 6 L060J3 60 GB and started backing up my main drive and moving some movie projects to it.
I initialized the drive using the Disk Utility.
I used Finder to copy almost 55 GB of data to the initialized drive.
I attemped to use the 'eject' icon in finder to disconnect the drive so that I could remove power and move some things around my desk. The drive did not 'eject'.
I disconnected the USB cable from the G4 and got the warning message from OSX.
I powered down the drive and moved things around then attempted to reconnect the USB drive.
I repeatedly got a "Volume not found" error with the correct name of the drive. The drive still appeard in the finder pane.
I attempted to verify and repair the disk using the Disk Utility, which still recognized the disk, but was still getting the "Volume not found" error when I attemtped to access the drive using Finder.
I used the disk utility to verify and repair the G4 system disk, at which time the USB drive dissapeared from the Finder window.
Now, attempts to reconnect the drive, do not show the drive as present in the Finder window, yet:
- when I disconnect the drive, I get a warning about stopping a device
- the drive still appears in the list of drives in the disk utlity app.
Any ideas on how I can get this drive to work again? I spent a lot of time dumping video into iMovie from my digital camcorder and I'd like to avoid reformatting the drive.
P.S. What is the correct way to shutdown and remove an external drive?
Thanks,
Larry Ice
12" Powerbook G4 Mac OS X (10.4.6)

The proper way to shut down and remove the drive is to unmount it (drag it to the trash) and then power down the drive before you unplug the usb cable. If the eject icon didn't work you should have tried dragging to the trash. If that didn't work go to Disk Utility and unmount from there. if that didn't work try Repairing the drive from Disk Utility. I would not have pulled the usb cable as you did.

Performance Issues with 10.6.7 and External USB Drives

I've had a few performance issues come up with the latest 10.6.7 that seem to be related to external USB drives. I have a 2TB USB drive tha I have my iMovie content on this drive and after 10.6.7 update, iMovie is almost unusable. Finder even seems slow when browsing files on this drive as well. It seems like any access to the drive is delayed in all applications. Before the update, the performance was acceptable, but now it almost unusable. Most of the files on this drive are large dv files.
Anyone else experience this?

Matt,
If you want help, please start your own thread here:
http://discussions.apple.com/forum.jspa?forumID=1339&start=0
And if your previous thread you aren't getting sufficient help for your iPhone, post a new topic here:
http://discussions.apple.com/forum.jspa?forumID=1139
You'll get a wider audience, and won't confuse the original poster. Performance issues can be caused by numerous issues as outlined in my FAQ*
http://www.macmaps.com/Macosxspeed.html
If every person who had a performance issue posted to this thread, we'd never find a solution for the initial poster. Let's isolate each case one by one. It is NOT necessarily the same issue, even if the symptoms are the same. There are numerous contributing factors at work with computers, and if we don't isolate them, we'll never get to the root cause.

How can i create a Trash for external USB Drives ?

Hello,
how can i create a Trash for external USB Drives or my TimeCapsule ?
Thanks.

You do not need to create trash cans for individual drives. The trash can on the desktop holds deleted files from all mounted drives.
TimeCapsule manages its own space. If it fills up it will delete older backps to make space for newer ones.

How can I do backups on internal disc while sharing an external USB drive?

Hi,
On my Airport Utility there are two lines: "Time Capsule Disc", and below (indented) "Data".
(When I plug an external USB drive I can see it in this window as well)
Clicking (selecting) the first line, on the right hand side I can see the disc details (name, capacity and SMART Status (Verified)), and two buttons: Compress and Erase (I don't know if these are the words used on the english version mine is spanish).
Clicking on the second line (Data) I can see the Name "Data", capacity, used and available sizes and number of users connected.
First question:
Why Time Machine can't see the "Data" volume if I untick the "Share files" checkbox?
Second question:
Moreover, I've got a USB External Drive attached to my Time Capsule, so I have to have the "Share Files" checkbox ON, this makes my USB disc (fat32) available to my Windows computers but ALSO the "Data" volume can be seen from Windows. If there is any attempt to assign a Windows drive letter to the "Data" volume, next time Time machine wants to do a backup I'm getting a "disc wrong or missing, check credentials (or something similar)".
In summary, what I'm trying to do is Time Machine backups to the internal Time Capsule disc (making that disc unavailable/invisible to any other computer in my network) while sharing a USB external drive attached to Time Capsule.
Advice, please!

Yes you can go to > Music > iTunes folder and copy the whole iTunes folder and drag the folder to your external and then on the new Mac click and highlight the iTunes folder and then in iTunes click on the button at the top (add folder to library) and you should see all your songs transfer from the external to the Mac and all songs start filling up in your iTunes library on the Mac.
This is the easiest method all songs and other media such as songs, movies, apps will be transferred over however you may not be able to keep ratings & last played counts using this method.
To keep all metadata including ratings & play count use the Apple method exclusively for this if you have to have your metadata, play counts and ratings saved.
I used scenario one above because it one of the simplest methods and I was just satisfied enough just to transfer all media over.

I would like to recover my bookmarks from my old hard drive that I now have as an external USB drive. The old OS was Vista; the new is Windows 7.

I recently had a new hard drive installed on my laptop; this hard drive has the Windows 7 OS on it.
At the same time, I had my old hard drive mounted in an SATB enclosure so that I could use it as an external USB drive. [I stupidly did not export my bookmarks before doing all of this]
Everything seems to work fine [I can see all of the files], but I cannot find out where my bookmarks are stored on the old hard drive.
Is it possible to find them and get them transferred over to the new hard drive??
Thanks!!

Bookmarks are stored in a file called places.sqlite inside the profile folder. You can copy that file from the old profile folder into your current profile folder. For details of how to find the profile folder see https://support.mozilla.com/kb/Profiles or http://kb.mozillazine.org/Profile_folder_-_Firefox
You can recover more than just the bookmarks - https://support.mozilla.com/kb/Recovering+important+data+from+an+old+profile

My external USB drive is not recognized by Win XP

Hi!
I have an external USB drive that is HTF+ formatted. It is not recognized by Windows XP. If I start the windows disk manager it gives me the option to initialize the drive. Do I dare to do this? Will it not erase the information on the drive?
Thanks for any help!
/ Anders

Hi Anders and welcome to Discussions,
I have an external USB drive that is HTF+ formatted. It is not recognized by Windows XP. If I start the windows disk manager it gives me the option to initialize the drive. Do I dare to do this? Will it not erase the information on the drive?
Yes it will !!
Although with the BootCamp 3.0 Drivers (from the OSX Snow Leopard DVD) and the 3.1 Driver update (downloadable) Apple has introduced read-access to HFS+ partitions from Windows this feature seems to have some serious problems for some people.
Personally I see this feature as "experimental" at the moment.
XP itself knows nothing and therefor can not use/see HFS+ partitions and GPT (GUID partition table) harddisks.
You might wanna have a look (or buy) at MacDrive http://www.mediafour.com/products/macdrive/ which right now is the better solution.
Thanks for any help!
/ Anders
Hope it helps
Stefan

Mini doesn't always connect bluetooth and external (USB) drives on boot

I have had a new Intel mini for 4 months now (we also have a PPC G5, which we love). In the last few weeks the mini started to not connect my Bluetooth keyboard and mouse, nor recognize some of my USB peripherals when booting up. When this happens, it also makes a repeated "startup sound - bong!" echo when the start button is pressed. I have two external USB drives, one 500GB Phantom and one 500GB WD MyBook. When the Apple logo appears at boot, I can see the activity lights flashing on the drives as the BIOS interrogates the USB connections, but after the Leopard start up desktop appears, the only drive shown is Macintosh HD, the mouse pointer is at the top left of the display and will not move, nor will the keyboard do anything. I have read every post on this subject and tried all of the resets suggested. Sometimes this works after a few attempts, sometimes it takes 6 or more tries - disconnecting all cables, and turning the computer on again and again. Occasionally the WD MyBook drive appears on the desktop, yet still the Bluetooth is unresponsive and the other drive absent. I am getting frustrated having to disconnect everything and trying to boot this thing up, sometimes for one hour or longer before I can use it properly (all of my work is on the external drives).
There MUST be a firmware update for this by now, because I see that I am not the only one experiencing these problems, and this is obviously some problem with how the BIOS is communicating with the bus.

Hi amyta pdx-
I'd be careful jumping to conclusions or the troubleshooting process may get clouded. For one thing those WD drives are junk and most people using them eventually have problems.
What happens with everything disconnected from the Mac except a mouse connected to a USB port on the Mac and the monitor connected to the video port only?
Luck-
-DP

Can a time machine usb drive backup the data from an external usb drive connected to and airport extreme*

can a time machine usb drive conected to my mac book backup the data from an external usb drive connected to and airport extreme ?

Hi Adam, if you think yoiur HD may be failing you could do a TM restore onto the new disk. I would rather see you do a clone either SuperDuper or CarbonCopy Cloner.Of your internal drive. That way you have a bootable backup in case it does fail.
btw - what are the symptoms of your failing drive?
-mj
Message was edited by: macjack

Errors on external USB drive

I'm trying to track down the cause of failed backups to a brand-new 300Gb Seagate drive in a external USB <-> SATA enclosure.
I observe these errors in Retrospects verification phase.
These errors could
- be 10.4.6 not playing well with external USB drives - that the new drive is essentially DOA
- that the enclosure is a dud.
- reflect an inability on Retrospect's part (e.g. unable to work properly with USB drives on 10.4.6)
I've asked on the EMC Retrospect forum for their take on this, buts that's a very slow forum...
Any pointers are welcome. I strongly prefer not to have to buy commercial solutions; after all, the "fix" may be to ask the supplier to take his drive back and refund me and I wouldn't want to spend if that's the case. Command-line solutions are fine.
The data can be correctly backed up to another external drive (via Firewire) so its not the source data. Its not the specific USB port: tried other ports, etc. At one point there were some errors reported by Disk Utility, but I've repaired these and it now claims all is well.
Dual G5/2Ghz/4GB RAM Mac OS X (10.4.6) ExternalUSB enclosure; 300Gb Seagate SATA drive

I see my question is so popular, I'm left composing a soliloquy... :-/
Anyway, an upgrade to OS X 10.4.7 (from 10.4.6) seems to have put this right, after a lot of different testing exercises and reading. At least for the first time in many attempts I've been able to run a sizeable backup using Retrospect without the verification pass yielding hundreds of errors.
It would seem, at least for Retropsect users, that OS X 10.4.6 needs to be avoided if you intend backing up to an external USB drive--?
Dual G5/2.0Ghz/4GB RAM

Reformat a single partion on an external USB drive?

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