How to recover data from Fusion Drive HHD with SSD together

[zhoubolin]

Guys do you guys know How to recover data from Apple Fusion Drive?
I was able to retrieve some data from the internal HDD with Disk drill however some of the file are incomplete, and learn that need to do with the Apple SSD.

 

[paardenkapper]

Fusion drives are just harddrives with an ssd as cache module.
The HDD should hold all the data you need and want.

If the filesystem is corrupted however there are heaps of tools that could restore it.
What exactly happened?

 

[zhoubolin]

thanks for letting me know that Fusion drives are just harddrives with an ssd as cache module.
that the HDD should hold all the data, because I saw this video and assuming that both HDD and SSD are needed

also I forget to mention that there is another partition02 (window bootcamp) in the HDD, and I only use the creating dmg image from that specific partition01. Is that the reason why getting some data from the internal HDD with Disk drill has some of the file are incomplete?

 

[paardenkapper]

thanks for letting me know that Fusion drives are just harddrives with an ssd as cache module.
that the HDD should hold all the data, because I saw this video and assuming that both HDD and SSD are needed

In theory you should only need the HDD to access your data but what exactly happened?

also I forget to mention that there is another partition02 (window bootcamp) in the HDD, and I only use the creating dmg image from that specific partition01. Is that the reason why getting some data from the internal HDD with Disk drill has some of the file are incomplete?

The thing is that all drives you want to recover from should be mounted read-only - there is a great chance you overwrite sectors of your harddrive if you keep on using it for writing.

 

[ignatius345]

Fusion drives are just harddrives with an ssd as cache module.
The HDD should hold all the data you need and want.

This is incorrect. Hard drives with caches (as described above) do exist, but Apple's Fusion Drive is not one of them.

Although it's composed of two separate physical drives, a Fusion Drive is a single logical volume in the OS. If either of the physical drives is damaged, the data will be irretrievably lost. Sorry to be the bearer of bad news, but as you're likely already discovering, you will be unable to recover data from either of the drives.

 

[paardenkapper]

This is incorrect. Hard drives with caches (as described above) do exist, but Apple's Fusion Drive is not one of them.

Although it's composed of two separate physical drives, a Fusion Drive is a single logical volume in the OS. If either of the physical drives is damaged, the data will be irretrievably lost. Sorry to be the bearer of bad news, but as you're likely already discovering, you will be unable to recover data from either of the drives.

I just broke it down to simplify the matter - of course the Fusion Drive is created by diskutil as a logical unit but the SSD part is mainly used as a cache and frequently used data is moved to the SSD but the main storage is the HDD.

It was a gap technology and just as RAID is no backup this isn't either. You should always consider setting up a time machine for example.

 

[ignatius345]

I just broke it down to simplify the matter - of course the Fusion Drive is created by diskutil as a logical unit but the SSD part is mainly used as a cache and frequently used data is moved to the SSD but the main storage is the HDD.

Perhaps oversimplified, I'd say: "In theory you should only need the HDD to access your data"

I'm not sure what the recovery situation would be in one of those hybrid drives you were equating Fusion Drives with, but in this case, data is lost if the drives are separated or one is damaged.

It was a gap technology and just as RAID is no backup this isn't either. You should always consider setting up a time machine for example.

Yes, fully aware it never offered any redundancy and that backups are crucial. Seems that in the OP's case that horse has left the barn already.

 

[Fishrrman]

OP:

Unless you have a backup, you're probably out-of-luck for much or all of that data.

Some data-recovery outfits may have the capability to "get the data back", but you'd have to send them both of the drives (SSD + HDD), and their services are VERY expensive (we're talking thousands of dollars).

Did one of the drives fail? (I'm thinking "SSD")

What options (if any) does disk utility give you, when booted to INTERNET recovery?
(that's command-OPTION-R at boot)
Any option to "re-fuse" the two drives?

You aren't the first person asking about a failed fusion drive, and I doubt you'll be the last.
Indeed, I expect MANY more posts with similar problems in the future.

My recommendation:
Time to look for a new Mac -- one WITHOUT a fusion drive.
Go forth from this day, and learn -- a sadder, but wiser, man.

 

[floral]

Now I see why people hate fusion drives. They're twice as likely to go wraps 3;

 

[FreakinEurekan]

Perhaps oversimplified, I'd say: "In theory you should only need the HDD to access your data"

But not, really. The combination of SSD and HDD as a Fusion Drive, does NOT move “All data” to the HDD. Individual data is almost always entirely on the HDD or entirely on the SSD, not on both. Data that you use frequently, would have more of a chance of being SSD data (so not on the HDD at all) than something you don’t touch often.

I’ve never tried to recover data from a HDD-only part of a Fusion Drive pairing because, you know, I back up my !@#$ (sorry OP) but theoretically “Some” files could probably be retrieved, and “Some” files would not be on the HDD at all. Exactly how you’d retrieve what is there, I have no idea.

 

[ignatius345]

But not, really. The combination of SSD and HDD as a Fusion Drive, does NOT move “All data” to the HDD. Individual data is almost always entirely on the HDD or entirely on the SSD, not on both. Data that you use frequently, would have more of a chance of being SSD data (so not on the HDD at all) than something you don’t touch often.

Exactly. Not sure how one would get from there to "you should only need the HDD to access your data" -- there's no way to back up that statement. I suppose anything is possible, but I have not heard of anyone recovering data at all from a broken Fusion Drive.

 

[ignatius345]

Now I see why people hate fusion drives. They're twice as likely to go wraps 3;

They were a very clever little setup back when SSDs were crazy expensive -- but those days are over, and any remaining Fusion Drives still in active use will probably all be dying pretty soon. If nothing else, the tiny SSDs Apple used are getting thrashed by all the read/write cycles they undergo with all that data being constantly shuttled back and forth.

 

[judyg951]

The Fusion Drive in my iMac lasted the life of the computer (8 years). I have the HD and it spins, but I can't get it to mount. Thank goodness I have the data on Time Machine. I don't have the Ssd and the tech that took it apart says it's the only drive in the machine. I'll have to go back over and get it from him.

Update. After I sent him a link for a Youtube video and talked more with him he was able to locate the drive and I'll pick it up tomorrow. I actually had to convince him that a Fusion Drive really existed.

I have the SSD blade drive now, but just hoping that I can use Time Machine to recover everything and start my new Mini Pro with it.

 

[judyg951]

I did end up restoring the drive to my new Mini using Time Machine. It took a long time, but then I had more than 50% on the 1T drive used and it's all good now.

 

[rin67630]

Fusion drives are a nightmare.
Wherever I can and when the SSD is 128GB, I split the FD, format the SDD to APFS, the HDD to HFS+ and install macOS on the SDD keeping the user data on the HDD.
The gives a snappy system, much more stable than a fusion drive.

 

[judyg951]

Apple used the Fusion Drive on the iMac. I still have a 10 year old one that’s still working, but after the one I used died recently I’m less trustful of thie one and want to replace it with another mini.

 

[macguru9999]

So... tonight's repair job :got a 2017 imac with a 3TB fusion drive. Drive does not boot or show up , fusion appears broken no partition on the spinner BUT imac has some weird I/O issues and I suspected a motherboard issue. ... so I cut it open and removed the spinner putting it in an external adapter. Then, I restarted the imac in target mode. I attached both to my computer using the TB3/USB ports on my mac pro 7,1. It WORKS, and I am now cloning the drive to an external to recover the files. (customer had no backup) I know I could have removed the mobo ssd from the imac but i was lazy and wanted to see if target mode would work, and it does..

 

[Fishrrman]

VERY clever move in reply 17 above!

So... even though the HDD portion was outside (via adapter), the OS was still able to "detect" the presence of both drives and "fuse them together" to enter target disk mode...?

That's important to know.
I sense there are going to be more "failures" like this in the future.
And your method "points the way" towards at least getting the data back.

 

[Mr_Brightside_@]

So... tonight's repair job :got a 2017 imac with a 3TB fusion drive. Drive does not boot or show up , fusion appears broken no partition on the spinner BUT imac has some weird I/O issues and I suspected a motherboard issue. ... so I cut it open and removed the spinner putting it in an external adapter. Then, I restarted the imac in target mode. I attached both to my computer using the TB3/USB ports on my mac pro 7,1. It WORKS, and I am now cloning the drive to an external to recover the files. (customer had no backup) I know I could have removed the mobo ssd from the imac but i was lazy and wanted to see if target mode would work, and it does..

I had something similar - similar symptoms - for a client where a friend had already attempted a repair, without realizing that
1) it was Fusion or
2) that Fusion was two pieces
I had recommended TDM and was told it wasn't working, and when I got everything, it was a cut open iMac with a separate 3.5" and the SSD still on the board...reconnecting the 3.5" internally to the mac (because I was lazy) and booting to target disk mode worked beautifully and I cloned 99% of data via DiskWarrior (no APFS).

 

[rin67630]

and I am now cloning the drive to an external to recover the files.

Did you succeed in recovering something?
Fusion drives are known to be useless without the other part.
I had the same situation. FD broken, the SSD blade defective.
If you leave the defective SDD on the logic board, you can work, but the defective SSD will still interfere with the boot process. If a drive shows up in diskutil list. but cannot be formatted it must be removed or replaced.

 

[macguru9999]

Did you succeed in recovering something?
Fusion drives are known to be useless without the other part.
I had the same situation. FD broken, the SSD blade defective.
If you leave the defective SDD on the logic board, you can work, but the defective SSD will still interfere with the boot process. If a drive shows up in diskutil list. but cannot be formatted it must be removed or replaced.

Yes, i got everything, a complete clone the imac mobo was faulty, not the fusion components. The spinner was connected externally via usb, and the ssd via thunderbolt from the imac in target mode... (in this case i did not need to remove the ssd and saved a bit of work)

 

[rin67630]

Yes, i got everything, a complete clone the imac mobo was faulty, not the fusion components. The spinner was connected externally via usb, and the ssd via thunderbolt from the imac in target mode... (in this case i did not need to remove the ssd and saved a bit of work)

Ah OK.
A relatively rare case, that the logic board was defective, but still functional in target mode.
Normally one of the disks fails and then, everything is lost.

 

[macguru9999]

Ah OK.
A relatively rare case, that the logic board was defective, but still functional in target mode.
Normally one of the disks fails and then, everything is lost.

Yes its usually the spinner that fails, it may in that case still be possible to boot the mac off an external drive and do a recovery, but if its a complete spinner failure then all is lost. I took a drive for a client to a data recovery place once and they were able to put the platters in another drive of the same model (!) so if you warned them that it was part of a fusion couplet and they did not mess around too much with the data, even that might be possible at great expense.

 

[rin67630]

Yes its usually the spinner that fails, it may in that case still be possible to boot the mac off an external drive and do a recovery, but if its a complete spinner failure then all is lost. I took a drive for a client to a data recovery place once and they were able to put the platters in another drive of the same model (!) so if you warned them that it was part of a fusion couplet and they did not mess around too much with the data, even that might be possible at great expense.

it's more common that the SSD blade fails.
If you take out the HDD alone, you might get some chunks of data from the HDD with e.g. Testdisk or Photorec, but since the inodes are on SSD the structure of the data is lost.
And that only if your FD was formatted hfs+ with an old macOS.
If your HDD was formatted APFS, you are 100% screwed: il is so badly fragmented that, without structure a recovery will be impossible.

 

[macguru9999]

it's more common that the SSD blade fails.
If you take out the HDD alone, you might get some chunks of data from the HDD with e.g. Testdisk or Photorec, but since the inodes are on SSD the structure of the data is lost.
And that only if your FD was formatted hfs+ with an old macOS.
If your HDD was formatted APFS, you are 100% screwed: il is so badly fragmented that, without structure a recovery will be impossible.

Not in my experience. I have seen more than 20 examples and its nearly always been the spinner that fails/failing. (I have seen apple ssds that have failed in 2012-2015 macbooks, however.) The whole concept of using an ssd, especially an early model ssd, as a frequently written buffer is a time bomb. Also, when you have to use low level tools the results you get rarely please the customer because all their structure is gone... i usually just refer them to a data recovery specialist and they usually wont pay 1000 and just give up. Diskwarrior was great in the old days... useless now in the apfs era. I downloaded diskdrill to try the other day but did not need it.