Converting ext disks to GUID partition scheme without erasing

I've got a few external hard drives that I've been using for a few years, and I just tried to encrypt them...only to be told by OS X that they need to have the GUID partition scheme. Is there a way to give them this without erasing their contents? They're big drives and close to full. Most of them are backup drives, so I'd really prefer not to erase them, nor do I want to buy a new drive just to use as a copy machine.

Unfortunately, you do need to erase the drive to partition GUID
http://support.apple.com/kb/TS1600

Similar Messages

  • TimeMachine Fails with PowerPC / GUID Partition Scheme / 10.5.2

    Just a short question to clear something up:
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    After the update, I get the following console message:
    2008-02-14 18:49:06 /System/Library/CoreServices/backupd[450] Error: Volume at path /Volumes/Satinav does not appear to be the correct backup volume for this computer.
    2008-02-14 18:49:06 /System/Library/CoreServices/backupd[450] Backup failed with error: 18
    [This article|http://docs.info.apple.com/article.html?artnum=306932] explains that Time Machine disks should be partitioned with the Apple Partition Map when used with PowerPC-based Macs. If that's so – why did the backup work before the update? Any explanations? Any solutions without having to re-partitioning the entire drive?
    Message was edited by: Kaspar Manz

    Repairing the Hard Drive and Permissions
    Open Disk Utility in your Utilities folder. 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 shutdown the computer for a couple of minutes and then restart normally.
    If DU reports errors it cannot fix, then you will need Disk Warrior (4.0 for Tiger, and 4.1 for Leopard) and/or TechTool Pro (4.6.1 for Leopard) 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.

  • GUID Partition Scheme - Need clean install: can I restore files from TM?

    So, here's my problem. I have an Intel PowerMac (first series after the G5) and when I try to install SL I get the following error message: "Can't Install Snow Leopard Since Disk Does Not Use GUID Partition Scheme". I guess it's something related to the fact thet I previously upgraded from an old iMac with a PPC processor (Apple partition vs. GUID partition).
    Anyway, accoding to my understanding, the only solution for me is to do a clean install by wiping the HD and re-partitioning it.
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    "Anyway, accoding to my understanding, the only solution for me is to do a clean install by wiping the HD and re-partitioning it."
    Right, except that your drive will automatically be erased when you set up the GUID partitiion.
    "Now, my question is: can I use my current TM backup to later restore apps/prefs onto the new SL system? I believe that TM now has an Apple partition scheme that reflects the one I have on Leopard 10.5. Is that right? Will I encounter any problem because of the different partition type of TM?"
    Your TM backup should work. But, there are not many guarantees in life. You could tranfer you TM backup temporarily to your internal and then make a bootable clone of your internal on your external. Afterwards, you could transfer the TM backup back. Then, you'd have two sources from which you could restore items.
    Message was edited by: donv (The Ghost)

  • Can't format SSD to GUID Partition Scheme

    I can't format my SSD to GUID Partition Scheme with Mac OS Extended(Journaled) but Master Boot works fine. When i try, it stucks even i tried Recovery HD. You can see issue in picture. What should i do?
    MBP Mid 2012 OS X Yosemite 10.10.2
    SSD is Samsung SSD 840 EVO

    c_arslan wrote:
    Toshiba is the current boot drive. I can't use the SSD because of the format of it. So there is SSD inside without format, filesystem etc.
    In that case, since the SSD likely came with an MBR Partition Map, at the beginning of your format process, did you choose the Partition button, pull down the drop-down menu under Partition Layout, and choose 1 Partition, and then, using the Options button at the bottom, select GUID?

  • HT2434 does anybody know what happens if I dont update the firmware of my macbook pro (does not have a guid partition scheme))

    does anybody know what happens if I dont update the firmware of my macbook pro (does not have a guid partition scheme)?

    Apple will hire a high school girls clique to follow you around, make fun of you & post disparaging comments on Facebook .

  • Unable to change to GUID partition scheme so Snow Leopard can be installed

    Upgrading from OS 10.5.8 to Snow Leopard 10.6.3 on Macbook 4.1 with Intel Core 2 Duo, 2GB RAM. Instructions state "Macintosh HD" can't be used because it does not use the GUID partition Table Scheme. Use Disk Utility to change the partition scheme. Select the disk, use the Partition Tab, select the Volume Scheme, and then select Options.
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    TOSHIBA MK1655GSXF Media
    Type :
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    Disk Identifier :
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    Media Name :
    TOSHIBA MK1655GSXF Media
    Media Type :
    Generic
    Connection Bus :
    Serial ATA 2
    How do I change the partition scheme to GUID?

    This requires that you repartition the entire drive as follows:
    Drive Preparation
    1. 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.
    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. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
    4. At this point you can quit DU and return to the installer and install Snow Leopard.
    If you have data you wish to save then you need to backup before doing the above.

  • RAID1 set shows Apple_HFS partition, although disks had GUID partition

    I am trying to build a RAID1 set for backup purposes from 2 external disks (Firewire connected). Disk 1 has one partition with GUID. Disk 2 has 2 partitions with GUID, number 1 of these partitions with the same size as disk 1 is used for the RAID set. When I build the RAID set with Disk Utility, the set gets Apple_HFS partition, and the 2 volumes have partition type "Apple_RAID". The set cannot be used as a bootable disk for an Intel Machine. Is this a bug?

    The Intel® Mac uses a different hard disk format scheme than the
    PowerPC Mac. Reformatting to GUID is said to work with FireWire
    drives, and not necessarily as good with some USB 2.0 units.
    TMO Quick Tip - Format a Drive to Boot Intel Macs:
    http://www.macobserver.com/tip/2006/08/16.1.shtml
    The Apple Partition Map and HFS+ have certain limitations in an
    Intel® Mac configuration where an external hard disk drive is set
    to boot and run a computer from a viable clone or backup scheme.
    Since I don't do all that fancy stuff, I am not experienced enough
    to further comment; mine use CCC to HFS+ formatted FW HDD
    and I make manual clones of my entire computers to partitions;
    bootable copies of everything, when I get around to doing it!
    Good luck & happy computing!

  • How do I change the partition scheme to use GUID partition Table.

    How do I change the partition scheme to use GUID partition Table so I can get Snow Leopard to download on my 10.5 disk.
    When I insert the disk it asks me to select  the disk where you want to install MAC OS X.It only give me one option the 10.5.
    when I click on it it says...
    "10.5" can't be used because it doesn't use the GUID Partition Table scheme.
    Use Disk Utility to change the partition scheme.  Select the disk, choose the Partition tab, select the Volume Scheme and then click Options. 
    I tried to do what it says and I can not find what it is saying.  This is the info about my MacBook.
    Model Name: MacBook
      Model Identifier: MacBook4,1
      Processor Name: Intel Core 2 Duo
      Processor Speed: 2.4 GHz
      Number Of Processors: 1
      Total Number Of Cores: 2
      L2 Cache: 3 MB
      Memory: 4 GB
      Bus Speed: 800 MHz
      Boot ROM Version: MB41.00C1.B00
      SMC Version (system): 1.31f0
    Thank you for your help!

    The GUID partition option is one of three possible choices (click the "Options" button in the Partition") menu - be careful to have a full backup as changing the partition scheme will force an erasure on the disk. Take a look at this Apple support article for more complete information:
    Firmware updates for Intel-based Macs require a GUID partition scheme - Apple Support
    Ignore the stuff about firmware updates and just look at the changing GUID partition scheme.
    Good luck - and don't forget about the full backup BEFORE making this sort of change.

  • Guid partitioning

    Have a MacBook with OS X 10.6.8 and downloaded Lion.
    It won't install - says "the disk does not use the GUID partition scheme"
    What is the best way to fix this without loosing all my data on the hard disk drive.
    Disk utility says I have "Partition map scheme: Master Boot Record"
    and "Mac OS Extended (journaled)"
    Thanks

    Actually it is reported that even though OSX refuses to install to non-GUID partitions for Intel machines, if you clone OSX to an APM drive it will still work with an Intel Machine. What you have done sounds fine, especially if you don't think you will ever want to install OSX directly on that second drive with an Intel machine.

  • Input / Output Error when creating GUID Partition on External Drives

    I've been trying to setup an install of OS X on an external device and therefore need to partition them to the GUID Partition Scheme.
    I've tried it with my iPod and an External Hard Disk Drive and no matter what I do, I get the error:
    Exited with Error: Input / Output Error
    Thats all I get. I can partition them with either of the other two choices, but of course those wont let me boot an Intel Based Mac.
    The External HDD is USB 2.0, the iPod I've tried both USB and Firewire, and have not had any luck. I know it can be done, but am not sure why I'm having this problem.
    Any suggestions?

    I'm having the same problem. Trying to format an external drive with the GUID scheme fails.
    # diskutil eraseDisk HFS+ Test GPTFormat /dev/disk1
    Started erase on disk disk1
    Creating Partition Map
    error writing partition map: Invalid argument (22)
    Partitioning encountered error Invalid argument (22) on disk disk1
    I've tried this on my Intel MacBook and on my PPC Mac Mini. Tried using a generic USB2 flash disk and also an iPod shuffle. Always the same error.
    Is GUID broken on external drives?

  • PPC Mac restore from GUID Partition on exterior HDD?

    In order to provide a bootable backup for my Intel iMac, I plan to reformat my external firewire/USB HDD (Maxtor OneTouch II) into several partitions using the GUID partition scheme. My question is whether I can use the remaining partitions on the Maxtor to do non-bootable backups of my G4 and iBook computers. With respect to my iBook, for example, if I clone its hard drive to one of the Maxtor GUID partitions, can I then, booting from the iBook installation disk, use DU to restore it back to my iBook as a fully functional system? My objective is to avoid buying a second external hard drive to support the PPC Macs.
    Intel iMac, 20", 1GB   Mac OS X (10.4.7)  
    Intel iMac, 20", 1GB   Mac OS X (10.4.7)  

    Hi-
    It's best to just get a retail version of Leopard for your PPC machine, especially since asking how to use the install discs from one machine, which are licensed to only one machine, is asking someone to tell you how to violate the EULA.

  • GUID partition format not on menu

    Trying to create a clone & need to format external drive in GUID. The rub is that GUID is not among the options in Disk Utility (OSX 10.4.8). How do I cut this Ghordian knot?

    In Disk Utility an entire disk can be set to the GUID partition scheme by selecting the drive (not volume) in the list>Partition>Option (button) a drop down sheet will appear to select the scheme.
    HTH
    W1

  • Disk Utility - smallest partition size

    I have new 500 GB external drive. Using Disk Utility I created GUID partition schema and created 4 partition - 3 x Mac OS Extended (Journaled) a 1 x FAT32 (initially with same size). Disk Utility doesn't let me resize 1st partion (the highest one) and 4th partition (the lowest one) smaller then cca. 50 GB (divider with 2 arrows changed to divider with 1 arrow). (I don't know if it's possible with other partitions to size them smaller then cca. 50 GB since I want them have large and I use disk already.) I didn't find anything about this in help, books or internet.
    Is there limit in Disk Utility about minimum partition size? (It looks like cca. 10 % from drive size).

    V.K. wrote:
    it looks like DU will not allow you to create a partition smaller than one tenth of the disk size.
    when i do it on a 200GB drive the smallest size it let's me make is 20Gb, and for a 500GB drive it's 50GB.
    I guess that's a safeguard against creating too many partitions.
    Message was edited by: V.K.
    I thought so. Like most filesystems, all the information must be stored in the bootsector or whatever it's called with BSD, and the total number of files is related to the sizes and total numbers of partitions, so like FAT32 or even NTFS, HFS has it's practical and theoretical limits.
    I believe HFS has two bootrecords or equivalents, one for backup and this adds to the storage space issue.
    Going back to the old 1.44MB floppies, the unformatted size was over 1.7 MB and Norton and MS took advantage of that, but not all disk readers were happy with what they did. MS once shipped Windows on a set of 1.7 MB floppies. Of course this was BC (before CDs).

  • Is there a partition scheme for both powerpc and intel-based macs?

    I need to partition a drive to back up using time machine from two different Macs: one is powerpc and one is intel but disk utility seems to only allow you to choose on or the other.
    this is the disk utility option:
    Select a new partition scheme:
    * Use Apple Partition Map partition scheme if the disk will be used with Time Machine and a PowerPC-based Mac.
    * Use GUID partition scheme if the disk will be used with Time Machine and a Intel-based Mac.

    silvrmn wrote:
    unfortunately i am alternating them between computers.
    is there a way to make it work or is the only solution to get two different drives and format them accordingly?
    TM will most likely work fine with both computers if you partition the drive GUID. that's been the experience of most people who do it. but apple does recommend partitioning the TM drive GUID for backing up intel macs and APM for PPC ones.
    using GUID is unlikely to create problems but it may.
    but if you want safety on this you'll need two separate drives.

  • Choosing an External drive partition scheme

    I have a 1 TB LaCie drive that I am currently using with a MBR partition scheme. It has two partitions: one for time machine and one for windows.
    What I want is to use this drive to hold my time machine back ups in one partition for Lion, which I am about to switch to and install on the iMac internal drive, my windows stuff in one partition, and a third partition in which I would put a clone (CCC) of my current internal drive (Snow Leopard) that I could boot from when desired. This would enable me to run Lion normally from the iMac's internal drive, switch to the windows partition (holding down the option key when powering on) on occasion when I want to work in a windows only app, and using the same option key on power on trick, boot into Snow Leopard when I need to use old, apps that won't run on Lion.
    For this, I assume that I should use the GUID partition scheme. Am I right? Is there a better way to accomplish my goal?
    Stephen

    Just a cautionary word about putting all your backups on the same drive: hard drives fail - they all do; some sooner than others....... I have several partitions on mine; however, I have three external drives, so everything is backed up x 3 (redundancy is good for backups).
    Having said that, I don't run Windows, so I can't help with that part; for an external to be bootable with a Mac, yes, you need GUID partition scheme. It's also a great idea to put a bootable clone of your Snow Leopard install on one just in case - that is the easiest way to revert if a major problem arises. I've heard there are some external drives which cannot boot a Mac, so make sure yours is. And, you may want to have another partition for your new (not yet installed) Lion install...... so I think I just made you run out of available space on your external 

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