Partioning High Sierra with another drive

Discussion in 'macOS High Sierra (10.13)' started by gw0gvq, Jun 8, 2018.

  1. gw0gvq Contributor

    gw0gvq

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    #1
    I want to Partion my High Sierra Hard Drive. But when I tried yesterday (as I thought, was the correct way) It portioned into 3 drives. Can so'meone please tell me how I can partition it into two drives only please.' Id like to know where I went wrong.' lol
     
  2. treekram macrumors 68000

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    #2
    If you can use the Terminal app and post the results of the command "diskutil list", that would help.

    If you haven't used Terminal (in the Utilities folder in the Applications folder) before, you can do the following:
    1) Start the Terminal app.
    2) At the top menu, click "Shell", select "New Command".
    3) Type in "diskutil list" and press the Run button.
    4) A window with the results will come up. You can copy/paste. If you wish not to have the volume names disclosed, you can edit it.
     
  3. gw0gvq thread starter Contributor

    gw0gvq

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    #3

    Here it is below. The terminal findings



    /dev/disk0 (internal, physical):

    #: TYPE NAME SIZE IDENTIFIER

    0: GUID_partition_scheme *251.0 GB disk0

    1: EFI EFI 209.7 MB disk0s1

    2: Apple_APFS Container disk1 250.8 GB disk0s2


    /dev/disk1 (synthesized):

    #: TYPE NAME SIZE IDENTIFIER

    0: APFS Container Scheme - +250.8 GB disk1

    Physical Store disk0s2

    1: APFS Volume Macintosh HD 34.1 GB disk1s1

    2: APFS Volume Preboot 40.3 MB disk1s2

    3: APFS Volume Recovery 1.0 GB disk1s3

    4: APFS Volume VM 2.1 GB disk1s4
     
  4. treekram macrumors 68000

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    #4
    With the new file system in High Sierra (APFS), you have a physical partitioning and a synthesized partitioning. Partition 0 isn't really a partition per se, so for the physical partitioning you have 2 partitions - the EFI partition, which is normal and the APFS container.

    For the synthesized partitioning, what you have is now the "new normal" when APFS is used.

    So what you have is normal - you did nothing wrong.

    Do you want to have another partition? If so, why do you want to have another partition? The question is not meant to pry or be perjorative, but now with APFS, if you want to add another partition, you can either have another physical partition or another synthesized partition. If you're looking to partition your disk for Boot Camp, Apple says to use Boot Camp Assistant. If you're just looking to add a second partition to separate your data, then Apple suggests you "Add a volume to an APFS container".

    https://support.apple.com/guide/disk-utility/partition-a-physical-disk-dskutl14027/mac

    If you look at your diskutil report, you'll notice that your Macintosh HD has only 34.1GB of space. That's because the containers in APFS can be dynamically sized.

    Now there may be a reason to have another physical partition - which can be done in Disk Utility (I haven't ventured into that part of Disk Utility yet).

    I'm presuming in all of this that your disk is the system/boot disk. If this is a second or external disk, then perhaps perhaps you would want to do something else - you'll need to provide more information.
     
  5. gw0gvq thread starter Contributor

    gw0gvq

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    #5
    I was going to put the Beta on it when it goes public. Well what I cant understand is wont 3 drives show up in the mac when the other OS is put in and how about the synthesized drive?
     
  6. treekram macrumors 68000

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    #6
    I think you'll have to follow whatever Apple suggests in regards to this. There would be definite advantages to putting it as another partition in the container. But I don't know how it will treat the recovery partition - will a second one be created, will it overwrite the High Sierra one? Also, I'm not sure how you boot in one vs. the other. Right now, the boot manager when I go into it just shows the bootable physical partitions.

    If you do a physical partition, there will be 3 partitions - the EFI, the APFS for HS and the APFS (if you go that route) for Mojave. If you do a synthesized partition, good question - I would guess one for the Mojave OS, it would not create one for Preboot or VM and maybe one more for the recovery. If somebody knows the answer, hopefully they'll respond. I'm a registered developer - I can see if I can find information on this but it may take some time.
     
  7. gw0gvq thread starter Contributor

    gw0gvq

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    #7
    I did it on Yosemite but that was a different setup. As regards booting you just turn the mac on and hold the ALT key then your presented with 2 drives and you boot into the one you want. you have a point mind now with the reactions.
     
  8. treekram macrumors 68000

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    #8
    I have a 2014 Mini which had one SSD running Sierra. I then put a second SSD in and installed High Sierra with APFS. So at this point I had a APFS SSD and a HFS+ SSD. When press the alt/option key at boot in this configuration, I was given the choice of Sierra, Sierra recovery (both HFS+) and High Sierra (APFS). The recovery volume in the APFS container did not show up - because it's synthesized? Probably if I boot into recovery, it would show up. So physical partitions show, synthesized didn't. So that brings the question of are synthesized bootable partitions visible? And I'm not seeing obvious answers in my cursor web search. This is a crucial question if you're going to put Mojave in the same APFS container where High Sierra also exists.

    Anyway, I don't see any mention of High Sierra and Mojave co-existence in the same APFS container, either on the web in another cursory search or in the Mojave release notes available on the Apple Developers' site.

    It would be just way too easy to have High Sierra and Mojave exist on the same container and then be able to use a boot manager to go into one or the other. I mean, to me, that's what APFS was meant to facilitate. And your question on the best way to do this is a good question. I need to do more searching on the Apple Developer site.
     
  9. gw0gvq thread starter Contributor

    gw0gvq

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    #9
    Yes when you gave the fors and againsts, bells started ringing for me re. High Sierra and Mojave existing together on a APFS Drive. I didn't think but for Partitioning an SSD I think there were fewer complications I don't know why Apple changed it. I suppose it was too easy for someone to make mistakes.
     
  10. treekram macrumors 68000

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    #10
    There are two big advantages to adding another volume/partition on an existing APFS container for what you want to do - try out Mojave (Mojave may actually want more volumes for recovery and preboot). The first is you don't have to do anything now - you're ready for Mojave when the public beta is available. The second is that you don't have to worry about what size you should allocate to Mojave vs. High Sierra - it will be dynamically sized.

    If APFS works well separating the volumes in the container, then you don't have to worry about having both OS's in a single container. But this is a new frontier - having multiple macOS versions on a single disk previously required a separate physical partition/volume.

    I looked on the Apple developer forum and there were posts that hinted that this can be done, but there is an article, in Italian, that goes through the steps of how this can be done once the public beta is released (again, you don't have to do anything until that time). According to this article, both High Sierra and Mojave should show up when you do the boot with the alt/option key held down - if not, you can change the startup OS in System Preferences.
    https://translate.google.com/transl...0-14-dual-boot-macos-high-sierra/&prev=search

    If you wish to have a separate physical partition/volume for High Sierra and Mojave, you need to resize the existing APFS partition. That Apple link I had earlier in post #4 doesn't cover it. I found this link - it looks fine but I haven't gone through steps. Keep in mind because you're modifying the system drive, this needs to be done with Disk Utility in recovery mode.
    https://www.howtogeek.com/212836/ho...artition-wipe-repair-restore-and-copy-drives/

    With creating separate physical partitions, it's better to create the separate partitions sooner than later. Supposedly with APFS, the need to do that is reduced - my guess would be that as long as you don't really fill up the disk with High Sierra stuff, it'll be OK to wait until you're ready to install Mojave before creating the new APFS volume. Maybe by then an English explanation of how to do this will appear.
     
  11. gw0gvq thread starter Contributor

    gw0gvq

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    #11
    Yes that's what I was going to do that's why I did the formating before. I have put a 50GB partition on so I have more for high Sierra.
     
  12. treekram macrumors 68000

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    #12
  13. gw0gvq thread starter Contributor

    gw0gvq

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    #13
    Thanks a lot for the heads up . now its been confirmed I'll have a go. I have an old MacBook Pro that I was thinking of putting it on but I don't know if it would be outdated for it . I had a job putting High Sierra on , but Id rather have a dual boot with the beta on because its more convenient for me , because I'm a wheelchair user and don't want to keep swapping all the time. Thanks again.
     

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