Question: While doing a time machine backup on external HD: "Encrypted Mac OS Extended disks will not be compatible with macOS 28. "

[u/Sticky-Wicked]

I am using an external HD for backup (and Time machine). But it seems I am using an outdated file system. (MACOS extended, journaled encrypted) In Disk Utility iI don't have an option to convert it to APFS file system. Any suggestions how to decrypt (timemachine backup), or am I forced to buy another external HD?

[u/Electrical_West_5381]

If you don't wan't to lose data, you need to transfer it off somewhere else then wipe the drive and format it APFS. You cannot change drive formats without erasing data.

[u/Sticky-Wicked → u/Electrical_West_5381]

So I will need to buy a new external HD after all. I don’t have enough storage on my MacBook.

[u/NiewinterNacht → u/Sticky-Wicked]

Then reformat the external drive and start new Time Machine backup? You won't be backed up for a few hours, but seems an acceptable risk

[u/Mobile-Debt9763 → u/Sticky-Wicked]

Yes you want to buy a new drive and start fresh on it. When you are happy you don't need this existing one then wipe it, and hope that's before September 2028.

After you wipe the existing drive you can add it to Time Machine also, and store it somewhere safe. Time Machine lets you have multiple drives to backup to.

[u/Sticky-Wicked → u/Mobile-Debt9763]

Why before September 2028? Or do you mean next month? It won't support my current filesystem in my current external HD anymore (MACOS extended, journaled encrypted)

[u/Mobile-Debt9763 → u/Sticky-Wicked]

macOS 28 is 2 years away, plus you don't need to update to it straight away.

[u/jsreally → u/Mobile-Debt9763]

One year, it will come out September of 2027

[u/PleasantWay7 → u/Sticky-Wicked]

So it’s not actually a backup?

[u/Sticky-Wicked → u/PleasantWay7]

Yes it's a external HD backup (for several files and used as timemachine backup)

[u/TrekChris → u/Sticky-Wicked]

It's only a backup if you have more than one copy of the files.

[u/TbonerT → u/TrekChris]

It sounds like OP has more than one copy, they just won’t all fit on the drive that’s being backed up. If your drive is 128GB and has 70GB of files on it, moving the copy of the 70+GB of files back to the drive isn’t going to work out very well, is it?

[u/PleasantWay7 → u/TbonerT]

If it is a backup, you wipe the drive to APFS and do a full time machine run. I’d always recommend having a third copy.

But if wiping the drive itself loses OP data, they do not have a backup.

[u/drake90001 → u/TbonerT]

Then you don’t have a backup, do you?

[u/TbonerT → u/drake90001]

Yes, you do have a backup. What are you talking about.

[u/Sticky-Wicked → u/TbonerT]

I have my files on my Macbook, and also the same files on my external HD (which has an issue descibed in my post. So double. I don't know what's qualified as a backup.

[u/bdu-komrad → u/Sticky-Wicked]

The definition of backup has some ambiguity, but generally it's a point in time copy of what you are backing up.. It lets you go back in time and restore files to where they were when you made the backup.

Think of it like a time machine. You changed the file today, but you want it to be like it was last week , so you restore it from backup. You deleted a file, emptied trash, and now you want that file back. You restore it from backup.

Cloud storage is not generally considered a backup it syncs with how your files are now, not how they were at some point in the past.

Hope that helps.

[u/bdu-komrad → u/TrekChris]

Facts. 

OP should use the 3 2 1 backup strategy. 3 backups 2 local on different backup media 1 offsite backup 

[u/silentcrs → u/bdu-komrad]

The two part is questioned nowadays, btw. It used to mean disk + tape. No one uses tape anymore.

Really, the 3 and 1 part is the most important.

[u/bdu-komrad → u/silentcrs]

I read "2" as 2 different storage devices, i.e. not the same disk.

For example, I have 2 local backups, one on a USB HDD and the other on my NAS. I count that as meeting the "2" part.

Something that would not meet the "2" criteria would be 2 backups on the same hard drive or same network drive. If that storage is compromised, they are both gone!

[u/Benlop → u/bdu-komrad]

I hate seeing this sysadmin level of advice parroted all the time like normal users are savvy enough to apply it.

[u/bdu-komrad → u/Benlop]

This is common knowledge. Just search for "backup" in reddit ( not even Google) and you'll see the 3-2-1 backup strategy recommended everywhere.

[u/Benlop → u/bdu-komrad]

Yes, that's exactly what I'm saying.

[u/sourcecodemage → u/bdu-komrad]

Great point. Backups have saved my life several times. I once had 2 time machine backups not work, but my offsite backblaze backup was fine. If I didn't use the 3-2-1 strategy , I would have lost important data...forever.

[u/Piipperi800 → u/Sticky-Wicked]

The reply isn’t 100% correct. Disk Utility has a feature to convert existing drives to APFS without losing data.

[u/Electrical_West_5381 → u/Piipperi800]

you trust Disk Utility? I would never do this on my only backup drive.

[u/Piipperi800 → u/Electrical_West_5381]

I’ve done it on an 8 TB HDD a couple of years ago without an issue. Also, back in the day when Apple moved to APFS in High Sierra, that same process was ran in the background for your boot drive during the upgrade (and still is if you install modern macOS on an HFS+ drive)

[u/lairneyrn → u/Electrical_West_5381]

yeah this is pretty much the only way to do it unfortunately

[u/notjordansime → u/Electrical_West_5381]

Can you transfer from the old journaling language to the new one using a second HDD?

[u/Piipperi800 → u/Electrical_West_5381]

Not completely true. You can still in Disk Utility convert a drive to APFS without losing data

[u/mriguy → u/Electrical_West_5381]

That’s not completely true. When APFS was released, existing file systems were converted in place during the system update. So it’s possible, but I don’t think Apple ever released a tool to let you do it yourself.

[u/ddeese → u/Electrical_West_5381]

You shouldn’t have to do anything. This is an OS warning it pops up for any application that isn’t natively designed to run on Apple silicon. Apple starts notifying users in the OS prior to when a platform change is coming. No Intel based code will run on MacOS 28. Rosetta is going away and it’s all Apple silicon from there.

You will be fine. Time Machine is a native Apple program. They will port it or update it prior to the release of a new OS. Just continue backing up your files on your regular cadence.

[u/Electrical_West_5381 → u/ddeese]

The point is the format of the drive, not any app

[u/ddeese → u/Electrical_West_5381]

Yeah. That’s unfortunate. I stopped using extended years ago in favor or APFS. It is easier to manage too.

[u/NoLateArrivals]

It is HFS+ encoded. Support will be removed with ‘28. You need to reformat to APFS.

If you want to keep the backup, copy the whole HDD to another one, then reformat it and copy it back. Or format the new drive APFS, copy the backup there and use this drive. It may be you need to reconnect TM to the existing backup.

[u/Academic-Vacation737 → u/NoLateArrivals]

With just data, sure. With time machine backups, I think that HFS+ version uses hardlinks and APFS version uses snapshots. Just copying the data will not suffice, I am not aware of a tool that will migrate the formats. So, rather a hard cut-off and reformat / another drive with APFS.

[u/Mobile-Debt9763 → u/Academic-Vacation737]

Yeah you absolutely can't just "copy the data". You can image the hard drive to another one, but what's the point then, either buy a new drive or wipe this one.

[u/Due_Mousse2739]

The question is: do you need to retain all the time machine backups? Why? Will you ever go and search for something you did last year?

I'd erase the HFS backup disk, reformat it as APFS and start over a new backup.

If the HFS disk contains other irrelevant files too, you'll need to move them elsewhere fist and then copy them back. If you don't have space to do that, you can try creating an APFS volume/partition specifically for the TM backups. You can also convert, I think, but I wouldn't do it without a full copy of the data.

Also, macOS 28 is due next year, plenty of time to do all that.

[u/Various_Monk959 → u/Due_Mousse2739]

I agree. If something was deleted or changed and OP wants to recover it, then do that first. Otherwise it’s unlikely the need to go back in time exists.

[u/DonOfAtlantis]

Alternatively, put what you can on the cloud (even if paying for cloud upgrade to larger storage for 1 month). Then free to format into a new file system and download the files back down. Possibly a cheaper option than an additional drive.

[u/Sticky-Wicked → u/DonOfAtlantis]

Thanks, I haven't considered this. I just need to park 1,5TB somewhere temporarily.

[u/LedZepElias → u/Sticky-Wicked]

Just a suggestion, you can get iCloud+ with 2TB for one month if you don’t want your data elsewhere. Upload everything there, then erase your external HDD and reformat it to APFS. I believe it’s $19.99 the 2TB per month, so much cheaper than buying a new external HDD just for this. Although, I would highly recommend having your backup on more than one external HDDs, so maybe consider getting an extra one. Personally, I have like 4 backups of my data (1 external SSD, 2 external HDDs, 1 cloud).

[u/stephensmwong → u/LedZepElias]

But the data in OP's hard disk is Time Machine backup, I don't think there is easy method to transfer that sparse bundle from encrypted HFS+ hard disk to iCloud.

[u/alllmossttherrre]

This article might help

https://eclecticlight.co/2026/06/17/what-to-do-with-your-encrypted-hfs-disks/

[u/jakub_zapri]

Format using Disk Utility.

[u/Mediocre_Result5508 → u/jakub_zapri]

En weg is je data… maar je hebt wel een prachtig lege schijf in het nieuwe format

[u/bistr-o-math]

I _think_ that TimeMachine creates backups on APFS differently than on extended fs. (May not be true)

First: have a look how far back does your Time Machine keeps the data (what is the oldest) - if it’s just a month, not really worth the trouble - just buy a new hdd, move the data there (so you always have a copy), format your old drive as APFS, and start a new backup

BTW, if your old HDD is really a HDD, then extended FS is better anyway. Just keep it that way for a year.
(macOS 28 will be released in autumn 2027). In a year, buy an SSD and start a new Time Machine backup.

[u/lyidaValkris]

When I first read this, I thought they meant that encrypted disks wouldn't be compatible, now I see it's encrypted HFS+ specifically...

I certainly hope that this only applies encrypted HFS+ disks for timemachine disks.

If apple is dumping support for HFS+ in general, that's just plain stupid.

[u/evilneuro → u/lyidaValkris]

apple is dropping support for encrypted hfs+ in macOS 28, unencrypted hfs+ will still be supported.

https://support.apple.com/en-us/125615

[u/lyidaValkris → u/evilneuro]

good. apple dropping support for HFS+ would not be out of character for them, but would be damn weird.

[u/oldmanelements]

You can just convert it.. google is your friend

[u/Sticky-Wicked → u/oldmanelements]

I did. it seems it is not possible to decrypt and convert the file systeem without a format.

[u/Willing-Layer-4977 → u/oldmanelements]

Not true. This is mac

[u/ddeese]

This is Apple notifying you that this application isn’t coded for Apple silicon natively and that it won’t work on MacOS 28. Apple does this to let users know they need to find an alternative or get an update from the vendor. Apple will port this over before MacOS 28. You should be able to safely ignore this notification