Caution - Yosemite may screw up partitions.

Discussion in 'OS X Yosemite (10.10)' started by yjchua95, Jun 5, 2014.

  1. yjchua95, Jun 5, 2014
    Last edited: Jun 5, 2014

    macrumors 604

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    #1
    Good day all,

    Just thought I'd give any potential Yosemite testers a heads-up.

    After installing Yosemite into a second partition in my internal SSD, I discovered that Yosemite had somehow messed up the partitions, to the point that:

    1. What used to appear as Apple SM0512F now appears as only Yosemite.

    2. Repairing disk permissions for the Yosemite partition is no longer possible. I have not tried repairing the disk from an external bootable drive yet, however.

    3. For the entire SSD, it's not possible to erase the SSD at all. I have not tried removing the Yosemite partition yet to see whether it's possible to erase the SSD or not.

    Anyway, I'm going to attempt to boot up from an external drive and see whether it's possible to erase the entire SSD from there. I'll post back with results.

    Update: It's not possible to erase the entire SSD. It's also not possible to remove the Yosemite partition, apparently. Repairing it from an external boot device comes up with an Invalid Disk Label @ 39341604864: cksum mismatch.

    Only after erasing the Yosemite partition, I was able to remove the Yosemite partition and restore the SSD to a single partition. Erasing the Yosemite partition also resulted in the drive label reverting back to its original name of Apple SSD SM0512F.

    TL;DR variant:

    The only problem users will face is that the user cannot verify/repair disk permissions for the Yosemite OS X partition, regardless of where you're trying to repair it from, be it from Yosemite itself or from another OS X installation.
     

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  2. m4v3r1ck, Jun 5, 2014
    Last edited: Jun 5, 2014

    macrumors 68000

    m4v3r1ck

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    #2
    Thanks for this! When I rebooted in Mavericks SSD, the option Repair Disk is added to the Yosemite SSD. Both options for permissions for Yosemite SSD are greyed out in disk utilities, regardless the OS X SSD booting from.

    ~ Cheers
     
  3. macrumors 6502a

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    #3
    It shows as invalid from Snow Leopard. Very strange. I wonder why this is. Mavericks, however, shows it normally, but there are some additional lines when verifying the partition with First Aid.
     
  4. macrumors 65816

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    #4
    I installed to a partition on an external drive, yet Yosemite installed boot code to my internal SSD. This surprised me. When Yosemite's bootstrap tried to find the external drive and couldn't, it offered to reinstall Yosemite for me.

    Changed my startup disk and was back to 10.9.3 after a reboot and all seems well, but just wanted to mention. This could be related to internet recovery though, just thought of it now and won't be able to check until later.
     
  5. macrumors member

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    #5
    I went and created a new partition from Yosemite for Mavericks after finding out that Final Cut Pro x was not compatible with Yosemite yet. Everything worked fine and Mavericks installed correctly, so creating partitions from Yosemite works well.
     
  6. macrumors 6502a

    stiligFox

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    #6
    Is it possible the drive is encrypted? I've heard that if the drive is encrypted it changes the name of the physical disk. Maybe Yosemite does this by default?
     
  7. macrumors 603

    bedifferent

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    #7
    Final Cut Pro X does work.

    A Fix for Final Cut Pro X!

    This works for Compressor and Motion as well. Been working well on my nMac Pro 8-Core system. Just run the executable in the package contents. I created an alias in Applications to save time, launches perfectly. :)
     
  8. macrumors P6

    Weaselboy

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    #8
    We were discussing this in another thread here and from the "diskutil list" output reported there, it looks like somehow Yosemite is converting the partition to a core storage volume, and that is why you see that double entry and not the drive brand name. Similar to what you see with Filevault or Fusion.

    If you look at my post #17 in that thread, you can try and delete the volume using the "diskutil cs delete" command from Terminal.
     
  9. macrumors 6502

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    #9
    I just posted in that thread too, I'm having the same issue.
     
  10. thread starter macrumors 604

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    #10
    Nope, the drive isn't encrypted.
     
  11. macrumors 604

    Jessica Lares

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    #11
    My drive wasn't encrypted either. A quick disk repair fixed my partition table though.

    You know... Something screwed up the iTunes permissions the last update too.
     
  12. thread starter macrumors 604

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    #12
    I've already submitted my issue to Apple through a bug report.

    Hopefully it'll be fixed in DP2 :)
     
  13. macrumors 6502

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    #13
    Hi Jessica

    Could you please describe what steps you took to fix the partition table? I tried to delete the core storage volume and lost the entire OS X system. The core storage volume is preventing me from repairing disk permissions or modifying the partitions via Disk Utility.
     
  14. macrumors 604

    Jessica Lares

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    #14
    Are you doing this within Yosemite? Or the Recovery partition?

    My drive is also still called OS X Yosemite too, but otherwise it's working as normal.

    I just did the usual steps of clicking "Repair Disk" under the First Aid tab.
     
  15. macrumors 6502

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    #15
    The option "Repair Disk" simply verified that the system volume was OK, but didn't modify the core storage properties to "revert" back to a normal partition. I've since downloaded a list of core storage commands and will try the following core storage command from an installation flash disk:

    diskutil coreStorage revert
    MountPoint|DiskIdentifier|DeviceNode|lvUUID
    [-stdinpassphrase | -passphrase [passphrase] | -recoverykeychain file]

    Convert a CoreStorage logical volume back to its native type.
    The file system must be mounted and resizable (i.e. Journaled HFS+).
    Ownership of the affected disk and a passphrase (if encrypted) is required.
    Reverting a CoreStorage volume completely returns it to its original state, including restoring the partition type and removing encryption. And it’s non-destructive. Slick!
     
  16. macrumors 6502a

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    #16
    I also tried repairing the main disk (I have 4 partitions currently, including Yosemite) - the main disk was also named Yosemite. I did a repair from both Mavericks and Recovery, but the name/type (Core) stuck.

    So, I run your exact commands and it'll restore the type? How do I fill out the mountpoint/diskidentifier/devicenode/vUUID parts? I'm still a bit confused. Do I do this from Recovery? Can you please clarify/expand - thanks!

     
  17. macrumors 6502

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    #17
    I would advise *against* doing anything now, unless you have a particular problem you're trying to solve. My partitions are just like yours, but I'm going to leave it that way for now because at least my Mavericks partition works fine right now and I'm a little nervous about screwing that up.
     
  18. macrumors P6

    Weaselboy

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    #18
    I don't think ssn637 has tried what he posted yet, and I'm not sure that it will work. What he posted is to change an encrypted core storage volume to a standard volume, but I think we have something else going on here with Yosemite. The Yosemite volume has been somehow converted to core storage, but it is not encrypted.

    If you want to get rid of that Yosemite partition, in an earlier post above I linked to my comment in another thread here that will work to kill it, then you can expand the remaining Mavs partition back into the now empty space.

    The command "diskutil cs list" will show the UUID info.

    But if you want to keep testing Yosemite, you might want to just leave things as they are for now.
     
  19. macrumors 6502a

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    #19
    How about if I want to convert the main partition? I'm baffled by why the main "home" partition table has been changed to Yosemite. I'm not sure if DP2 can fix this. Does that make any sense? Notice the 3 Yosemite partitions in the picture I've attached - one is the 'main' partition, and one is mountable, the other is not. I'm just concerned that my whole partition map has been hosed. Yes, it works fine now, but I'm thinking long-term. Before, the main partition was generically named - I believe it was the name of the actual HD, but not sure.
     

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  20. macrumors P6

    Weaselboy

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    #20
    I understand exactly what you mean, and it looks like that because of the way things work when creating core storage volumes. They get setup as logical volumes (partitions) and it makes Disk Util look like what you are seeing. Run the command "diskutil list" (without quotes) in Terminal and it will show you the volume layout and help you understand what is going on here.

    If you turn on Filevault or use a Fusion drive the same thing happens and you have that double name there instead of 128GB Apple SSD or whatever you had before.

    Here is my MBA with Filevault on under Mavs. Totally normal.

    [​IMG]

    The piece we just don't know yet is why a Yosemite install on a second internal partition makes that volume into a core storage volume. But it is not surprising the way Disk Util looks, as that is how it shows core storage volumes like Fusion or Filevault volumes.

    You can either leave it and keep on testing Yosemite, or blow off that partition following my linked post. Another user posted he was able to kill the partition following my post and get things back how they were, so I would not be too concerned about any harm from this. Hopefully you have backups from before all this though.
     
  21. macrumors newbie

    Tony.Skid

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    #21
    I've installed Yosemite on an external USB, everything wents well, slow but works.

    After a while, restarted with internal SSD and Mavericks, Time Machine started with a backup of 30GB... :eek:
     
  22. macrumors 6502a

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    #22
    Was the external HD plugged in?

     
  23. macrumors newbie

    Tony.Skid

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    #23
    Yes, but it was, and still is, excluded from backup.
     
  24. macrumors 6502a

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    #24
    That's very odd. Try restarting, holding Shift down while restarting, then Mavericks will boot to Safe Mode. When you get to the login screen, restart normally (don't press Shift again), then next time you're in Mavericks, try restarting the TM backup. Let me know what happens.
     
  25. macrumors newbie

    Tony.Skid

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    #25
    Before reading your suggestion, I did something different: restarted with recovery HD, repaired permissions on Mavericks (lot of corrections on iTunes. Maybe because Yosemite had updated iTunes?), then restarted. TM backup now is ending, with a total of 4.98GB. Still, very odd.... Any idea?
     

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