APFS on normal HDDs

timothevs

macrumors 6502
Original poster
Nov 17, 2007
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Has anyone tried to upgrade their HDDs from HFS+ to APFS? Any downsides or problems if you did?

I am quite curious if t would be worth upgrading my four HDDs on the 2012 Mac Pro.
 

thirdeyeopen666

macrumors 6502
Sep 16, 2007
436
100
Has anyone tried to upgrade their HDDs from HFS+ to APFS? Any downsides or problems if you did?

I am quite curious if t would be worth upgrading my four HDDs on the 2012 Mac Pro.
I converted the HD in my 2011 iMac (SSD+HD) without issue.
 

tmoerel

macrumors 6502
Jan 24, 2008
367
79
As APFS is optimised for SSD it might actually flood a spinning harddisk with commands and result in a lower performance than HFS+
 

phillytim

macrumors 65816
Aug 12, 2011
1,269
584
Philadelphia, PA
Does an install of High Sierra offer, or force, a conversion of existing HDD to APFS?

Has anyone with HDD done a seamless conversion to APFS without destroying their current macOS in use?
 

timothevs

macrumors 6502
Original poster
Nov 17, 2007
457
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As APFS is optimised for SSD it might actually flood a spinning harddisk with commands and result in a lower performance than HFS+
That would be disappointing. I was hoping to use it on my 10 TB drives - to prevent against bitrot.
 

Intell

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Jan 24, 2010
18,872
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APFS will support HDDs, but it currently does not in the first beta. You can still force enable it with various Terminal commands though, but it isn't pretty to do.
 

thirdeyeopen666

macrumors 6502
Sep 16, 2007
436
100
APFS will support HDDs, but it currently does not in the first beta. You can still force enable it with various Terminal commands though, but it isn't pretty to do.
I didn't have to do a single thing on the command line to convert my internal HD. Just right clicked it and selected Convert.
 

Intell

macrumors P6
Jan 24, 2010
18,872
368
Inside
That's because you have a Fusion drive, which is a supported auto-convert scheme. A plain HDD is not currently supported in some cases to auto-convert to APFS.
 

Spazturtle

macrumors member
Sep 17, 2013
44
23
APFS will convert HDDs, it's just that APFS doesn't supports drives using MBR it only works with GPT. So if your drive uses MBR you will need to format it to use GPT.

If your drive uses MBR when you right click convert in Disk Utility you should get Error 118.

You can use the terminal to force a drive using MBR to convert to APFS, but then your mac won't be able to mount the drive.

Use "diskutil list" in terminal to see what partition table all your drives use, if it says "GUID_partition_scheme" then you can convert that disk, if it says "Master Boot Record" then you need to reformat the drive.
 

thirdeyeopen666

macrumors 6502
Sep 16, 2007
436
100
That's because you have a Fusion drive, which is a supported auto-convert scheme. A plain HDD is not currently supported in some cases to auto-convert to APFS.
No, I do not have a fusion drive. As stated earlier, it is a 2011 iMac with both an SSD and an HDD. Partitioned as separate discs, as it came from the factory.
 

macintoshmac

macrumors 68040
May 13, 2010
3,054
2,642
As APFS is optimised for SSD it might actually flood a spinning harddisk with commands and result in a lower performance than HFS+
If a file system of today doesn't know the drive it is being slapped on is SSD or HDD and behave accordingly, it has failed already.

Which is not the case with APFS, it sings on mechanical HDDs, and in fact makes transfers very much faster.
 

Ries

macrumors 68020
Apr 21, 2007
2,095
2,441
That would be disappointing. I was hoping to use it on my 10 TB drives - to prevent against bitrot.
There is nothing in APFS to prevent or detect bitrot. There is some checksumming on metadata (as most modern file systems), but nothing on user data. Apple assumes data never is corrupted and the storage system never returns bogus data by claiming the hardware takes care of any such event (i.e. the EEC correction and such standard build-in features on SSD's)
 

timothevs

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Original poster
Nov 17, 2007
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There is nothing in APFS to prevent or detect bitrot. There is some checksumming on metadata (as most modern file systems), but nothing on user data. Apple assumes data never is corrupted and the storage system never returns bogus data by claiming the hardware takes care of any such event (i.e. the EEC correction and such standard build-in features on SSD's)
Ugh which is why I had hoped APFS would introduce it to the macOS world,as a replacement for ZFS, if only for the platter drives. Which now begs the question, what to do for 10TB odd drives. Use OpenZFS, or...?
 
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dolphin842

macrumors 65816
Jul 14, 2004
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I've been using OpenZFS for a while on my 5,1 Mac Pro. There are some quirks: throughput on certain io-intensive tasks (unzipping an app bundle, for instance) leaves much to be desired, but at least I know my data is ok. FreeNAS network drives are also an option if you're ok with the 1Gbit link speed.

But yeah, it's rather disappointing that after all the effort put into APFS, it was built assuming that bitrot doesn't exist at the hardware level. (If the APFS designers truly believe Apple hardware never returns bad data, why are they still checksumming the metadata?)
 

applepuree

macrumors 6502
Aug 15, 2014
367
506
My 2014 (late) Mac mini runs like a dog with HS, so I converted it to APFS, but no longer boots (some bless error). So backing out to Sierra and not installing the beta on that system for a couple of updates. Works fine on my 11" MBA.
 

dolphin842

macrumors 65816
Jul 14, 2004
1,168
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Looking at the slides for the APFS session, it has a new defragmentation process for HDDs that runs in the background during idle periods. Seems like it's more involved than the old 'hot files' feature of HFS+, so once it ships there should be an improvement for HDDs as well.
 

grahamperrin

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Jun 8, 2007
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dolphin842

macrumors 65816
Jul 14, 2004
1,168
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Thanks for linking to the APFS talk graham. I'm not sure if anyone knows the timing for defrag to start, and even if we did, it wouldn't surprise me if Apple tweaks things like that between now and release. The APFS docs on the developer site are still rather 'sparse' (pun definitely intended).
 
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grahamperrin

macrumors 601
Jun 8, 2007
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Thanks.

Now monitoring without touching, I have not yet observed anything that might be optimsation during system idle time. The HFS Plus volume was probably reasonably well optimised before conversion, so maybe no optimisation is necessary in my case.

Code:
highsierra:~ grahamperrin$ date ; uptime ; sw_vers
Sun Jun 11 22:00:37 BST 2017
22:00  up  3:22, 2 users, load averages: 0.79 0.63 0.68
ProductName:    Mac OS X
ProductVersion: 10.13
BuildVersion:   17A264c
highsierra:~ grahamperrin$ ioreg -c IOHIDSystem | awk '/HIDIdleTime/{print $NF/1000000000;exit}'
554.539
highsierra:~ grahamperrin$ ioreg -c IOHIDSystem | awk '/HIDIdleTime/{print $NF/1000000000;exit}'
651.932
highsierra:~ grahamperrin$ iostat -dIw 1
              disk0               disk1
    KB/t xfrs   MB     KB/t xfrs   MB
    1.79 594  1.04    11.64 1825293 20751.81
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     0.00   0  0.00
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
              disk0               disk1
    KB/t xfrs   MB     KB/t xfrs   MB
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
              disk0               disk1
    KB/t xfrs   MB     KB/t xfrs   MB
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
    0.00   0  0.00     7.48  23  0.17
^C
highsierra:~ grahamperrin$
 
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shrodz

macrumors newbie
Jun 23, 2017
1
0
Does an install of High Sierra offer, or force, a conversion of existing HDD to APFS?

Has anyone with HDD done a seamless conversion to APFS without destroying their current macOS in use?
The installer has an option to format the drive or not.
 

prostetnic

macrumors newbie
Jun 2, 2017
19
6
The installer does not offer the option if you only have an mechanical HDD.
Correct. But if after the upgrade you boot into recovery, you can choose to convert your disk in disk utility, even if it is a HDD
 

bbfc

macrumors 68040
Oct 22, 2011
3,128
678
Newcastle, England.
Correct. But if after the upgrade you boot into recovery, you can choose to convert your disk in disk utility, even if it is a HDD
Might try it. Beta 2 hasn’t made any difference on my early 2011 MacBook Pro. It still lags like hell and has horrible memory usage. Do you think converting the drive would help?
 

Tech198

macrumors G5
Mar 21, 2011
13,960
1,639
Australia, Perth
That would be disappointing. I was hoping to use it on my 10 TB drives - to prevent against bitrot.
The place u could try it out would be on a Mac mini... They never had SSD's :) unless u installed then afterwards.

I have MacOS Sierra on mine, so i may try getting the public beta for it and divide partition on the 1TB. With any luck it won't trash my Mac, but even if it does, i have a backup for my media. as its a home media server,but i add to iTunes from NAS anyway.
 
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