High Sierra (HFS+)...how are updates applied

[MarkC426]

Looking to update my main SSD from Sierra to HS, but don’t want APFS what with a spinny time machine and clones, I think it may get complicated.
If I update to HFS+ (will have to trawl the threads for the procedure....) when I install updates (if any now) will the update try to convert to APFS or is this only done during the first install?
Likewise will security updates do this also?

Just about cautious as I don’t think the installer tells you it’s about to convert (or am I wrong).

 

[BLUEDOG314]

If you are running a machine with a SSD, and upgrade to HS, it will automatically switch you to APFS. If memory serves, you can modify some scripts in the installer somewhere that tells it not to convert to APFS. TBH I would make sure you have a good backup and just let it convert. While calling APFS perfect is premature, most people that have issues with the conversion had issues long before the conversion, and the switch just brought things out in the open.

I work in an environment supporting a fair amount of macs, and have seen people who never restart there computer with an SSD that has say 5GB of free space running some flavor of El Capitan, and expect the HS upgrade to go well. Its just not reasonable to assume that. On the other hand I've personally upgraded 4 machines with no issue.

Further, with time machine, you still want to leave your backup drives formatted to HFS+ as APFS does not support hardlinks.

 

[MarkC426]

So the TM will still perform as normal on a hdd.
Also cloning to hdd from the APFS ssd, will this not be a problem if a restore is required?

 

[treekram]

So the TM will still perform as normal on a hdd.
Also cloning to hdd from the APFS ssd, will this not be a problem if a restore is required?

It depends on how you're doing the cloning. If it's something like CCC, make sure you have the version meant for APFS. I think SuperDuper has a APFS-compatible version. If not one of these software, what are you using?

 

[MarkC426]

Currently Superduper.

I am just not sure, if there was a problem how to access the APFS drive from an HFS+ volume, I was under the impression it wouldn’t be recognised.
I currently have a seperate drive with HS installed (for testing) which is only a hdd (HFS+).
So if I booted either from the HS hdd volume or the external clone would they recognise the APFS formatted drive?

 

[Honza1]

I have a bad feeling, that MarkC426 is confusing HFS+ and OSX version. If you have HS running, even if the system drive is HFS+, it can read and write APFS and all seems to work generally fine. However, you cannot access APFS from older versions on OSX. So if you have second computer with Leopard or any other older OSX version and attach APFS disk (external or internal), it will not see APFS and will not know what to do. This complicates downgrades as blasting off APFS and reformatting to HFS+ seems bit of complicated (at least for some).
TM MUST stay at HFS+ and actually, OSX will not convert TM disks to APFS on its own. You have to do it manually at which point TM fails and wants you to reformat the drive to HFS+.
Today (10.13.6), on standard systems, with HS installed on internal SSD, APFS seems generally fine. As any HD/SSD it can fail - my software created at one point error in the disk system which could not be fixed and I ended doing Clone-to-external...Format...restore on it. But that happened on HFS+ also, few times, so I am not blaming APFS.
In summary, unless you are doing something complicated, use APFS on internal SSDs. It works. If you plan to play with partitioning, Bootcamp and whatever else, APFS is somehow different and that causes issues. And non-Apple tools are not yet fully developed, so stay at HFS+ in that (specific) case...

 

[MarkC426]

Thanks for the explanation, I thought there where issues with a HFS+ drive reading APFS, but that’s not the case from your reply....thanks.
It is an internal ssd.
What do you mean by non-apple tools, are you referring to apps?

 

[Honza1]

Thanks for the explanation, I thought there where issues with a HFS+ drive reading APFS, but that’s not the case from your reply....thanks.
It is an internal ssd.
What do you mean by non-apple tools, are you referring to apps?

Yep,
Apple "Disk utility.app" works fine, but other apps (tools) have challenge catching up. However, Disk Utility.app cannot do everything which command line diskutil in OSX 10.13 can do... You are limited to relatively safe and reasonable set of capabilities... GUI is used to protect users from messing up too much.
But what about power users - or if something really fails? Non-Apple tools/apps used to open the capabilities more for GUI type users.
Someone said somewhere (take with grain of salt), that APFS specifications are not broadly available and are moving target. Until those specs stabilize, its bit challenging for makers of other tools/apps for disk management to keep up. For example, I heard (again, not sure how reliable it is) that APFS will have in the future hard links and will be able to be used for Time Machine. That may be significant change which may need major upgrade to all tools/apps. And the only ones who know all are Apple engineers.

Note - APFS has been used in the latest iOS versions and now in OSX version 10.13. There is A LOT of APFS disks running now, and generally just fine ;-)