APFS and Fusion Drives

It doesn't need to be ssd and hdd. Fusion drive works also with two SSD's.

 

I am sure that might be the case, but wasn't the point of a Fusion drive, for two reason, 1. cost of SSD drives, 2. wear and tear of the SSD drives. The spinning slower drive takes the brunt of the wear with commonly modified files, while fixed files, that don't change often go on the SSD.

The larger SSD drives are less expensive now, and the larger the drive, the longer the drives last, especially when using TRIM.

I still think with two SSD drives, it defeats the intent of an SSD, and would be more like a Redundant Array of Inter-spanned Disks. I suppose this could increase performance, if using a stripped array. I was under the impression though, that with SSD the seek time is so low, it also is not needed.

The only real benefit I could see would be to use two SSD as a Raid or fusion, would be for it to appear as one disk instead of two. Still, I would not do that.

 

What if you have the stock 125GB super fast PCIE storage (or 256 and 512) and you want to fuse it with a much slower Sata 1tb cheap SSD
It does make sense!

 

So if I purchase a high-end 2017 iMac with fusion drive next week it won't be compatible out-of-the-box with APFS, the main feature of HS?

That's disconcerting.

 

I was under the impression Apple was referring to automatic conversion only.

I take it users can still convert their fusion drive or mechanical HDD over to APFS manually?

 

I have an 27-inch iMac, late 2015, 1 TB Fusion drive.

After upgrading to High Sierra, I entered into recovery mode and started Disk utility. There I found that the disk could not be converted to APFS, because the option was grayed out.

I have gone back to Sierra.

 

Try using the beta 1 installer made from a USB install disk. I believe that it worked on that version. (I am sure apple stopped supporting it for a reason though.)

 

Good article: "APFS and High Sierra in trouble"

excerpt:

 

I have some confusion with the discussion and articles. I have Late 2014 27" iMac with 1.1TB fusion drive. That drive is formatted APFS (Encrypted). I installed two (or three?) public betas ago from a thumb drive - reformatted the drive from the installation Disk Utility. No hiccups during the installation or since.

 

This guy's blog often writes about "problems" that simply aren't as serious or alarming as he'd like people to think. This article seems to be another one of those.

 

Good article? I was laughting my ass with the APFS formatted usb stick argument! Like you can read NTSF with windos 95 or ext4 with older linux distro....if state the obvious with an allarming tone of apocalyptic nature is your thing ok...but don't call it a tech article. the guy revealed no technical information, nothing we don't know about it, is just another look at me I would do better than apple kind of blog....
Can we stop helping this useless bloggers gain visibility? What is his contribution except disconcern some non tech users.

So he is suggesting that apple should have postponed APFS so that your fusion drive could have it not later than the SSD users? Why? You will get it once is ready for your config, why should SSD users wait....what you gain?

 

I think you can use 2 SSD to form a Fusion drive. From memory, someone did it and tested it (but as far as I remember, only see 1 case, and I am not 100% sure if my memory is correct)

The reason to do that is pair a super fast PCIe SSD to provide top speed and a SATA SSD to provide capacity. In fact, system actually know that the PCIe SSD is faster, and will store data on the PCIe SSD first.

 

Apple File System.
Your data is under new management.
Your documents. Your photos. Your mail. Your apps. To your Mac, everything you care about is data. And a file system is what organizes all that data into files and folders you can access with a click. Our current file system was designed in the early days of Mac, and it has performed beautifully ever since. But today’s flash‑based Mac systems open up new possibilities for innovation, so it’s time to lay a new foundation. With macOS High Sierra, we’re introducing the Apple File System to every Mac with all‑flash internal storage, with an advanced architecture that brings a new level of security and responsiveness.

One can argue what 'introducing' means in the last sentence, for me it means that APFS is not going to be supported on fusion drives, at least not in the initial 10.13 release.

 

It's clear what Apple is saying: "we’re introducing the Apple File System to every Mac with all‑flash internal storage"

 

It appears different articles are pointing at different things, when it comes to supporting APFS on fusion drives. One of the article I've just read for admins covered the fusion drive compatibility issue, and gently breezed through it by saying it can be done manually but no urgent need to do so at this point in time.

 

I guess the only way to be sure is to wait for the GM and see if FD can be automatically/manually formatted in APFS at that point.

 

Isn't the GM already released?

 

Nope, still beta 9. GM for iOS 11 was released today however.

 

Wow. If my late 2015 fusion drive iMac dont support this, I'll just stick to Sierra for a while. There is no reason to upgrade now.

 

There was a presentation at WWDC about APFS which stated that there were improvements to Fusion drives when converted. When APFS is used on a Fusion drive all file metadata is moved to the SSD to speed up searching and indexing operations.

I myself built a fusion drive using two external drives, one SSD and one a spinner, and conversion to APFS worked fine.

 

Well, my late 2013 iMac (1TB fusion) is still running well with no APFS on high sierra so unless I get forced over, quite happy to have this as it is. But then I do a bit of home photo and video processing and light word processing etc. Nothing heavy. External hard drives for backup are quite large and no way in the world am I buy any SSD matching 4tb to replace them at the costs they are.

 

Here is the official link:
https://beta.apple.com/sp/betaprogram/apfsfusion

 

Wanted to install the GM and being forced now to reformat my drive to HFS+ and then reinstall/restore from Time Machine. What gives? I've been running APFS on my Fusion Drive since beta 1 without issues (aside from performance issues in beta 1-2).

Installer links to this page, telling me to start from scratch: https://beta.apple.com/sp/betaprogram/apfsfusion

 

Not sure if this has been posted already...

https://support.apple.com/en-gb/HT208018

I think a manual upgrade is possible through Disk Utility.

 

So according to this, Fusion Drives will not be supported in the initial release but only later...?

Has anyone tried to manually format an FD to APFS in GM yet?