APFS Optimized Install

[Infrared]

I’ve installed High Sierra to a disk containing an empty (i.e., newly formatted) HFS+ partition. I wonder, though, if it would have been better to have created an APFS volume from the start, rather than convert from the older filesystem type. By “better” I mean better in terms of performance and minimal legacy remnants. Is that the case?

Advice welcome.

Thanks!

 

[MacDawg]

I have no empirical data on the matter, but I would say in the long run it isn't likely to make a difference

 

[chrfr]

I’ve installed High Sierra to a disk containing an empty (i.e., newly formatted) HFS+ partition. I wonder, though, if it would have been better to have created an APFS volume from the start, rather than convert from the older filesystem type. By “better” I mean better in terms of performance and minimal legacy remnants. Is that the case?

Advice welcome.

Thanks!

It doesn't make a difference.

 

[maflynn]

I can't see how this will matter in the long run.

 

[Infrared]

Thanks for your replies. Could you perhaps elaborate providing specific technical detail?

 

[Mike Boreham]

I’ve installed High Sierra to a disk containing an empty (i.e., newly formatted) HFS+ partition. I wonder, though, if it would have been better to have created an APFS volume from the start, rather than convert from the older filesystem type. By “better” I mean better in terms of performance and minimal legacy remnants. Is that the case?

Advice welcome.

Thanks!

Some notes of caution here:

1. I am guessing the drive is an HDD? If it was an SSD then I would have expected the HS installer to have converted it to APFS automatically. There is a school of thought that APFS is best not used for HDDs at this time. However, Apple have only said APFS is optimised for SSD, and since Disk Utility supports formatting HDDs to APFS I assume it is supported. I have backup HDDs on APFS without problem

1. In the very early days of High Sierra I did what you did and then used the Disk Utility>Edit> Convert to APFS to convert it from HFS+ to APFS, which it apparently successfully did.....but that volume would not boot after doing this. Tried three separate times. I saw other reports of the same. I have not tried doing this recently. It may be fine now.

2. If you are booted from your HFS+ install, then I don't think the option to convert to APFS will be available. You need to be booted to another drive. Again this may have changed recently though it would seem very reasonable that macOS can't actually change the file system and partition map of the volume it is booted from. Recovery is different on an APFS drive so I don't think you could do it booted from Recovery on your HFS drive. APFS drives have other partitions on compared to HFS+.

3. Very recently I successfully converted all my external SSD data-only Samsung T3 and T5 drives from HFS to APFS using the Disk Utility edit tool.

I might try testing some of the things I have reported above with the latest version.

 

[T'hain Esh Kelch]

Thanks for your replies. Could you perhaps elaborate providing specific technical detail?

I assume it comes down not having any residual old legacy stuff lying around. Either the drive has one filesystem, or it has another. It doesn't end up with a weird mix.

 

[Mike Boreham]

Some notes of caution here:

1. I am guessing the drive is an HDD? If it was an SSD then I would have expected the HS installer to have converted it to APFS automatically. There is a school of thought that APFS is best not used for HDDs at this time. However, Apple have only said APFS is optimised for SSD, and since Disk Utility supports formatting HDDs to APFS I assume it is supported. I have backup HDDs on APFS without problem

1. In the very early days of High Sierra I did what you did and then used the Disk Utility>Edit> Convert to APFS to convert it from HFS+ to APFS, which it apparently successfully did.....but that volume would not boot after doing this. Tried three separate times. I saw other reports of the same. I have not tried doing this recently. It may be fine now.

2. If you are booted from your HFS+ install, then I don't think the option to convert to APFS will be available. You need to be booted to another drive. Again this may have changed recently though it would seem very reasonable that macOS can't actually change the file system and partition map of the volume it is booted from. Recovery is different on an APFS drive so I don't think you could do it booted from Recovery on your HFS drive. APFS drives have other partitions on compared to HFS+.

3. Very recently I successfully converted all my external SSD data-only Samsung T3 and T5 drives from HFS to APFS using the Disk Utility edit tool.

I might try testing some of the things I have reported above with the latest version.

I just did two test installs of 10.13.3, one onto an external HDD formatted HFS, and one onto an external SSD formatted HFS. What I found:

1. The external SSD was not converted to APFS by the install. The automatic conversion of SSD to APFS during install must only apply to internal SSD.

2. Disk Utility>Edit>Convert to APFS was greyed out for converting both the test installs, whether booted from the test installation, from Recovery or from another High Sierra volume. The last surprised me and was not the case for me in the early days of HS.

3. Disk Utility>Edit>Convert to APFS is not greyed and works on volumes which do not have an OS installed.

Maybe there is another way of converting an existing OS installed external HFS volume to APFS, but on the face of it you have to format it to APFS before installing.