Formatting a micro SD card

Discussion in 'Mac Basics and Help' started by Kobayagi, Oct 1, 2016.

  1. Kobayagi macrumors 6502a


    Dec 18, 2012
    Quick question, because I just can't find it on google.

    I have a 64gb micro Sd card (exFAT) which I want to split into two partitions. But it just won't work. The option to partition it is greyed out in Disk Utility, and I can't find a solution on google anywhere.


    The card needs to say in the exFAT format because I want to continue using it in my Sony camera. The reason it needs to be split in 2 (rather than just leave the photos in a separate folder on the card) is because Lightroom doesn't let me 'add' photos from the card to the Lightroom library since it recognizes it as a card that's used in a camera.

    So my plan is: take photos, save them on the card (I hope my camera will always 'pick' the right partition the save them on.) And every time I put the card in my MacBook, I'll transfer the photos from one partition to the other before loading them into Lightroom. It may seem cumbersome, but it really isn't, since a big card doesn't make me carry around a external hard drive. And saving them on my Mac isn't a great deal too with a 128gb ssd...

    I've looked into the Lightroom problem, which doesn't let me add photos from a sd card. It works perfectly great when they are on a external drive or usb stick. But Lightroom recognizes the camera folder structure and blocks you from importing from the card.

    So, I hope anyone knows whats up, why can't I just partition this card?
  2. JohnDS macrumors 65816

    Oct 25, 2015
    This link:

    suggests that you first reformat by as Apple Extended Format with a GUID partition map. This should result in the partition tab no longer being greyed out.

    Partition the drive, then reformat each partition as ExFat.

    Also, I don't understand your Lightroom problem. I always import to Lightroom from SD cards or CF cards from my Canon Camera.

    Perhaps LR needs an update to recognize the Sony format.
  3. chown33 macrumors 604

    Aug 9, 2009
    You need to select the item that says "Apple SD Card R...". That item represents the SD card as a whole.

    The screenshot shows you've selected "Sony NEX-6", which is a partition on the card. It's the only partition, but it's still a partition. Since you can't partition a partition, you can't get there from here.

    After getting the card partitioned, I recommend testing it thoroughly in the camera. By putting everything on one card, any errors will likely corrupt the whole card, and boom go all the photos on all partitions.
  4. JohnDS macrumors 65816

    Oct 25, 2015
    I think your problem with LR is that you should not be trying to "ADD" when importing from an SD card. Use COPY instead.

    When you use ADD, LR does not copy or move the files. It adds a reference to them in the library but the reference refers back to the SD card, not to your hard drive. If you then put the card back in your camera and format it, all the pictures are gone because they are not moved to the HD. It is to prevent that error that LR prevents you from using the ADD option in the import dialog box when it recognizes a card came from a camera.

    If you use the COPY option, LR will copy the files from the SD card onto your hard drive, which is what you want.

    Try that first before you partition your SD card.
  5. Kobayagi thread starter macrumors 6502a


    Dec 18, 2012
    Thanks I will give it a go, I'll report back with the results.

    About my Lightroom problem: I want Lightroom to reference to my photos from the sd card and not copy them from my card to my Mac, then make a referenced file from that new copy.

    It's explained here:

    "Anyway, Lightroom doesn’t have the Managed option. It will ONLY reference your images where they are on your hard drive. When you Import you’ll see an Add option and that’s the one to choose to tell Lightroom…"

    The problem is discussed here:

    User 'Bob Somrak' explains the problem:


    The OP is wanting to use an SD card as a drive. If you take the camera formatted SD card and try to ADD it does not work because Lightroom must be using the DCIM file structure on the card to identify it as a camera card. If you format it in the computer (In my case it was FAT 32) and place photos on it than Lightroom will treat the SD card as a removable drive and you can use all the import options, including ADD. At least on the MAC, Lightroom doesn't care if it is an SD, only if it has the standard DCIM file structure that all (at least the ones I have seen) the cameras are using when it disables ADD."

    His solution isn't for me because my Sony camera only reads exFAT.

    I did find a (rather cumbersome) workaround:

    After taking photos, move them to a new folder on the card and delete the DCIM structure -> eject the card -> put it back in -> open Lightroom and it works. If lets you 'add' them to LR. But after you're done editing, you will need to put back the DCIM folders so you can take photos again, otherwise you'd have to format the card while it's in the camera and this means losing all photos that are on the card, in a different folder.

    So you see, if I could partition it to something like 50gb and 14gb (approximately) I wouldn't need to delete and bring back the DCIM folders every time. 14gb would be enough for me to take photos since I'd move them to the other partition before running out of space.

    Anyway, thanks for the link. I'll give it a go.
    --- Post Merged, Oct 1, 2016 ---
    Yeah, exactly. But I would actually like LR to reference them to the card since I'd be using it as a 'hard drive' and card for the photos. It's all a storage problem tbh, If I had more storage on my MacBook I wouldn't need a big sd card and all photos would directly go on the ssd.
    --- Post Merged, Oct 1, 2016 ---
    Thanks, but I clicked there too, it's still greyed out. I'll try the link 'JohnDS' posted.
  6. JohnDS macrumors 65816

    Oct 25, 2015
    It seems to me that using the same card for the camera and as a drive is asking for trouble. What about backups, for instance? What happens when you fill the card? I have filled a 32 Gig card in an hour shooting birds.

    If your hard drive is not big enough to hold your photos, why not get a 64 GB thumb drive? Copy the photos from the card to the thumb drive, then use ADD from the thumb drive. Or use COPY to copy from the SD card to the thumb drive.
  7. Kobayagi thread starter macrumors 6502a


    Dec 18, 2012
    Yeah, maybe this wasn't the best plan, but since I don't take too many photos, 64gb seems more than enough. But because since Im referencing photos, I always need the card plugged in and can't take photos when it's in use.

    For backups, I was gonna copy them to my external drive, which is a 3,5".

    In the end, a thumb drive like you're suggesting is a better solution than keeping everything on one card.
  8. Kobayagi, Oct 3, 2016
    Last edited: Oct 3, 2016

    Kobayagi thread starter macrumors 6502a


    Dec 18, 2012
    It's still not working. When the sd card is selected, the option to choose the size by sliding the circle around is still not available.


    Any ideas?

    I also tried it with terminal, which would make this line of code for wanting 50gb on one side in ExFAT and the rest, also in ExFAT:

    diskutil partitionDisk disk1 2 MBR ExFAT Foto's 50G ExFAT Sony R




    I just used the code that was given on the link, one partition is in FAT32, which doesn't matter much, as long as the one the camera needs (the smaller one) is in ExFAT.
    --- Post Merged, Oct 3, 2016 ---
    Okay... I put the card back into the camera and when taking photos, the camera saves them on the bigger partition, which is FAT32, what is going on? :eek:


    Okay, I managed to partition it into two ExFAT partitions.
    I used this code:

    diskutil partitionDisk disk2 2 GPT ExFAT cam 50G ExFAT foto R

    On the camera: it's unable to take photos and asks for a format, which is ExFAT.... :p


    I give up, I'm going to leave it with this code:

    diskutil partitionDisk disk2 2 MBR MS-DOS DOSEXC 50G ExFAT Exexchange R

    It saves the photos on the bigger partition, then from there, I have to manually delete the DCIM folders -> unplug -> plug back in -> so LR doesn't recognize it as a card.

    Again, same hassle, but now with 2 partitions. :D

    Getting a 3tb drive very soon...
  9. Fishrrman macrumors P6


    Feb 20, 2009
    Seems like you're going through all kinds of twists and turns.

    I would do it this way (in fact it IS the way that I do it):

    - Get a USB card reader

    - Take card out of camera, put in card reader, connect to Mac. Card reader then mounts on desktop.

    - Now, use the finder to create a NEW FOLDER on your desktop. Give it any name you wish.

    - Next, MANUALLY COPY those pics you wish to move from the card into Lightroom, into the new folder you just created.

    - Eject the icon for the card reader, disconnect, put card back into camera.

    - NOW, you should be able to use Lightroom to find and import the files from the folder you have on your desktop.

    A few extra but simple steps.
    Gets the job done without a lot of hasslin' ...
  10. Kobayagi thread starter macrumors 6502a


    Dec 18, 2012
    Hi, thanks for your reply, but what you're suggesting is to copy the photos from my card onto the Mac. Obviously, this is the easiest and best solution, but as I said in a few posts above, it's a storage issue. I don't have a lot of free storage on my MacBook Air, the stuff that's on it right now is needed for college etc. so I can't just delete that. And I'm taking all photos in raw, so the files are big (16mb per photo), so If I had enough storage on the ssd, I would do it this way.

    But because I don't, I bought a big sd card, hoping I could store and acces the photos from there with Lightroom. The problem is, Lightroom doesn't let me just 'add' those photos into the library because it recognizes the DCIM folders..

    But I have worked it out, I'll just keep doing it this way as I described earlier:

    "I did find a (rather cumbersome) workaround:

    After taking photos, move them to a new folder on the card and delete the DCIM structure -> eject the card -> put it back in -> open Lightroom and it works. If lets you 'add' them to LR. But after you're done editing, you will need to put back the DCIM folders so you can take photos again, otherwise you'd have to format the card while it's in the camera and this means losing all photos that are on the card, in a different folder."

    And soon, I'm buying a external hard drive, which I'm going to store everything on + use it for Time Machine. So this problem is going to be fixed anyhow since I'll be taking the hard drive with me. This sd card trick I wanted to do was just a temporary solution.
  11. Michael Anthony macrumors regular

    Oct 18, 2012
    I've taken to using Gparted live CD .iso image in a VMWare Fusion virtual machine to do my formatting since OS 10.11 managed to royally screw up the built in Disk Utility.
  12. rwegner macrumors newbie

    Mar 14, 2018
  13. rwegner macrumors newbie

    Mar 14, 2018
    Thank you, Command Line fixes the issue.

    My Issue:

    macOS 10.12.6 Disk Utility would not Show Partition option for new Samsung 256GB EVOPlus MicroSD.
    I wanted to Create two Mac OS Extended (Journaled) Partitions, One partition of SupperDuper Image of my Boot Drive and seconed partition for backup of my Data Drive.

    The Fix (Command Line):

    MacbookPro2015-RW:~ rwegner$ diskutil partitionDisk disk2 2 GPT JHFS+ macOS_Boot_BK 150G JHFS+ macOD_Data_BK R

    Disk Utily Before Command:


    Running Command:


    Disk Utily after command:


    Note: To see everything diskutil can do view man pages of diskutil on you mac from the command prompt.

    To view diskutility man pages:

    MacbookPro2015-RW:~ rwegner$ man diskutil



    To exit Man Pages: [shift] [q]


    Thank you for your assistance.


  14. hobowankenobi macrumors 6502a

    Aug 27, 2015
    on the land line mr. smith.
    One workaround I have seen used for limited space:

    Leave a dedicated SD card in the Air slot, and use it as a second internal drive. Transfer photos over via a USB card reader.

    You can even get a flush, sexy, micro card adapter, and add a fast micro SD card, so nothing is projecting out to get damaged or unmounted.

    A decent workaround for a fairly cheap, manageable storage upgrade.
  15. mollyc macrumors 68000

    Aug 18, 2016
    I’d do the thumb drive or get a second card. Do you have room to offload your photos temporarily to your computer and then copy them to a second card?

    I would never want to risk using a card that goes in my camera also as a full storage device in case the card gets formatted IN THE CAMERA. Then everything is lost. Bad idea.

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14 October 1, 2016