Home Forums Mac Software Mac Operating Systems Contain your data in APFS

If you have a drive formatted APFS you can have multiple "Containers" sharing space on the drive. This OWC Rocket Yard article explains the how and why.

Volumes in a container can grow or shrink as needed, thus neatly avoiding my long held prejudice against partitioning a drive because criticaly needed space was/is always on the wrong partition. IMHO this deserves spending some time exploring the possibilities.

I did some reading up on partitioning APFS volumes the other day, because I'm trying to decide what to do when I finally upgrade to High Sierra. (Your linked article was one of the top hits.)

One option struck me as curious, because I can't think of a single reason to do it, and that's that you can set your partition sizes rather than leave them flexible.

Can you think of a reason why anyone would do that?

The thing that I love about it, though, is that it enables me to maintain more partitions than I could before, because with my not having to make size commitments they'll take up virtually -0- space until I need them.

After some more experimentation I have found [b]I made several mis-statements in this post so I am deleting the incorrect statements and will start over in the following post...

Originally Posted By: artie505

One option struck me as curious, because I can't think of a single reason to do it, and that's that you can set your partition sizes rather than leave them flexible.

Can you think of a reason why anyone would do that?

I agree, why would the vast majority of users give up the flexibility of expanding and contracting Containers and Volumes? I can see it being useful is special circumstances such as iOS app development or even MacOS applications development. This is pure speculation on my part, but could it be the fixed size is because of limitations for HFS+ volume structure?

In any case IMHO Apple still has work to do on Disk Utility and APFS including...

[*]Time Machine backup on APFS volumes [*]Full integration of APFS and RAID (OWC is working hard on that in their SoftRAID product) [*]APFS for Fusion drives [*]Declunking and deflaking Disk Utility (maybe an new UI altogether — DU has been around in essentially the same form for a long time and looks more and more like patchwork.)

CORRECTED VERSION

My experimentation with Partitions and Containers has so far revealed...

1. PARTITIONS:
   • Are applied at the device level
   • Always have a fixed size that is set in the disk partition map.
   • Contain one volume
   • That volume may be formatted Mac OS Extended (HFS+), FAT, EXFAT, or APFS
   • If the Partition is formatted APFS, it will have one Container and one or more APFS volumes in that Container
2. CONTAINERS:
   1. Are applied at that Partition level
   2. May have one or more "APFS Volumes" sharing the same space.
   3. Volumes in a Container may only be formatted APFS
   4. These volumes may expand and contract dynamically as needed and the only limit on the capacity of these volumes is the size of the Container.
3. DISK UTILITY:
   1. IMHO the GUI needs work
   2. CAUTION: After partitioning/re-partitioning a device or adding a Volume it is necessary to quit and restart Disk Utility to refresh the display and get accurate information. At least that is true in Disk Utility 17.0.3.
4. CONCLUSION:
   1. Containers overcome most, if not all, of the limitations of partitioning
   2. "Volume" and "APFS Volume" are bound to create a LOT of confusion among the less technically inclined and even among the very technically inclined unless they are carefully differentiated.
   3. As soon as I can resuscitate my test HDD I will verify that this works on HDDs as well as SSDs

Volumes can be created with with expansion/contraction flexibility, but are you certain about containers? I think their size is set once they're created. (Note: You corrected that in post #48938.)

If you can see any use for fixed sized volumes, I suppose it supports Apple's inclusion of the feature, although I'd think that separate containers would be more appropriate for app development.

As good and clear an analysis as that is, I agree that myriad users will still find it confusing, but for what it's worth, it ties in with my experience. (*)

I'll add that APFS volumes can be added to my flexible volumes container at will.

I'll also add that as opposed to the 150 MB used by an empty 50 GB HFS+ partition or the350 MB used by an empty 300 GB partition, an empty APFS volume uses only 90 KB of space.

(*) My Disk Utility experience differs from yours: I just added and deleted an APFS volume to/from my one container, and both actions were reflected immediately by Disk Utility Version 17.0.3 (1646).

More: I agree that Disk Utility's GUI needs work, but I also think that much of what's wrong with it is our unfamiliarity with the new info it's displaying. If it's all APFS, it's not too bad, but when you've got APFS containers and volumes, and HFS+ volumes in the same sidebar it gets confusing.

At any rate, it took a lot of forethought and patience, but I've upgraded to High Sierra and reformatted my internal SSD as APFS with one container comprising six volumes.

Finally!

Yaaay!!!

Congratulations on finally making the leap and just in time for the first beta release of MacOS 10.14!

RE: My issues with Disk Utility these screen shots submitted to Apple hopefully are self explanatory.

• Screenshot 1
• Screenshot 2
• Screenshot 3
• Screenshot 4

NOTE: The problems only happen when there is an APFS Volume involved. So far I have not been able to generate any issues with Mac OS Extended, FAT, or EXFAT volumes. I hve also found that as i continue to make changes without recycling Disk Utility the display and other glitches begin to cascade and grow. As long as I recycle after each operation there are no problems.

I was hoping for the 10.13.5 update first.

I haven't performed the same tests you did, but I have added/deleted volumes to/from an existing container, and those actions were recognized instantly by DU.

Adding a partition to my APFS formatted internal SSD either isn't possible, or I'm misunderstanding what I'm seeing:

• Every item - device, container, or volume - in my DU sidebar has "Partition" enabled.
• Clicking on each one returns the same "Creating a new volume is easier...." pop-up.
• When I persist and click on "Partition", I invariably get this pop-up which points to my SSD and tells me that it can't be split because it's not mounted, although, as you can see, "Mount" is greyed out, and since it's my boot device it must [I think] be mounted.
• And further, selecting my container shows "Mount" as an option although clicking on it does nothing that I can see.

Got me beat!