How do you create images with APFS?

[Marcel Risberg]

Originally Posted by TOM@METRO

Automatically? No. I always create and verify an image before any updates. This is not just with Windows, but any OS.

With Apples new filesystem - APFS, how do you create these images? Last time I checked, imaging APFS is not an endorsed or a supported technology, yet at least. Your answer might of course be that you're still on HFS.

[Darryl Ramm]

Originally Posted by Marcel Risberg

With Apples new filesystem - APFS, how do you create these images? Last time I checked, imaging APFS is not an endorsed or a supported technology, yet at least. Your answer might of course be that you're still on HFS.

To create clones/images of APFS volumes you just use any backup/cloning tool that works on APFS, or use standard UNIX volume or file copy/backup commands.

Lets start by getting terminology clear. APFS *snapshots* can be used to allow point in time recovery. Are made automatically by the system during some software upgrades, or can be made manually from the command line, or from third party tools like Carbon Copy Cloner.

APFS does not include a high-level cloning/images creation tool besides what you get with Time Machine. Third party image/cloning tools might or might not use the snapshot capability to provide more capabilities.... Carbon Copy Cloner does, and that is discussed in their documentation/website.



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[ChuckS]

CCC will clone an APFS drive to the same format. However CCC will not create an image file in the APFS format until Apple fixes some issues with the underlying image service. It will create a HFS+ image of your APFS disk. I would assume that the same issue applies to any third party imaging software.

https://bombich.com/blog/2018/02/15/...ed-disk-images

[Darryl Ramm]

Originally Posted by ChuckS

CCC will clone an APFS drive to the same format. However CCC will not create an image file in the APFS format until Apple fixes some issues with the underlying image service. It will create a HFS+ image of your APFS disk. I would assume that the same issue applies to any third party imaging software.



https://bombich.com/blog/2018/02/15/...ed-disk-images

Unfortunately this thread got moved (maybe a little too aggressive there DigiTechSupt?) from another thread so folks can't see the context of just creating disk clones prior to updating software. For that most people would not use Carbon Copy Cloner to create sparse disk images, they would instead use it to simply clone the drive to another (and/or now with Snapshot support maybe make a snapshot). I know you mention it, but to be really clear to people the above issue only affects copying to sparse disk disk images.

(Edit: I had confusingly mentioned "dmg", I meant just sparse disk images, this does not affect dmg images).

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[ChuckS]

I use CCC to create disk images (sparsebundles) on NAS as an additional backup. This is where I ran into the APFS imaging issues. I use straight up CCC clones as my primary. It's a heads up to anyone who might be more dependent on NAS or servers.

[jdh95]

Originally Posted by ChuckS

CCC will clone an APFS drive to the same format. However CCC will not create an image file in the APFS format until Apple fixes some issues with the underlying image service. It will create a HFS+ image of your APFS disk. I would assume that the same issue applies to any third party imaging software.

https://bombich.com/blog/2018/02/15/...ed-disk-images

I have used CCC 5.09 to make a sparseimage of APFS SSD to a HFS+ drive, but have yet to do a restore. Will this HFS+ CCC sparseimage of the APFS drive then correctly restore properly?

[Darryl Ramm]

Originally Posted by jdh95

I have used CCC 5.09 to make a sparseimage of APFS SSD to a HFS+ drive, but have yet to do a restore. Will this HFS+ CCC sparseimage of the APFS drive then correctly restore properly?

Nobody can ever guarantee your backups will work. You *have* to test they do. And here you are exposed to the issue mentioned above. The issue triggers when the sparse image uses APFS internally, regardless of the filesystem the image live on. But to trigger the problem you have to write enough to the sparse image that at some point (maybe in the past) you exceed the real physical free space on the underlying storage. Read that Bombich software article carefully, it tells you what to check. You can only be doing what you say you are doing if you created those volumes using an older version of CCC.

Backing up to sparse disk images to NAS can be convenient, nice say for automatic overnight backups. But you really want to think this all through. How do you recover a computer from those images if it had totally lost its boot drive, or you totally lost the entire computer? For that its often much more convenient to have a physical clone of at least the boot/system disk to get started. In many cases you could just plug that Thunderbolt or USB 3 drive into the Mac, reboot and just keep working. Recovery happens at the speed of a reboot.

If you are using any type of NAS backups to backup your boot/system drive, think through all the steps involved with doing a full recovery. Think about scenarios where the boot disk loses its content, the boot disk is totally dead, or the entire computer is gone/destroyed/stolen and then think through similar for the NAS server itself....hopefully you have extra onsite and offsite backups/archives. You can do lots of different things for recovering the boot drive, setup netboot images, boot off a special recovery drive, clone the sparse disk image back to a boot partition. It may need to use a spare unused partition, might use a spare blank external drive and clone to that from the NAS image using a third computer, etc. There are lots of ways to skin the cat, but you need a plan for one or more that you know works.

NAS can be a great way to back up user files and projects. But even then sparse image backup on a NAS might be overkill, I often prefer say just backing up working folders to folders on the NAS, manually dragging or dropping content or with low level scripts on the Mac. Some folks like time machine to a NAS, but it's not great for systems recovery, and gives you limited control of stuff, but hopefully Apple will improve it more, now they have APFS underneath time machine.