Fusion drive fails again

Back in April I had a few problems with the Fusion Drive on my 2014 iMac. So much so that I had to copy the data off the iMac onto an external drive and then reformat the drive and reinstall OS X.

Having got back to where I had been before the drive failed I was happy with going back to work on the iMac. However I was suspicious that the drive might fail again. I kept regular backups of files and photos, but I did have an expectation that the drive might fail again.

On Saturday it did just that. I was using the iMac to sort out some train tickets and other tickets when it just froze. Nothing was working, so I switched it off at the back and when I switched it back on I was rather downhearted, but not really surprised, to see the prohibitory symbol.

I booted into Recovery mode (hold down the Command and R keys when turning on and release once you see the Apple logo or a spinning globe). I ran disk utility which confirmed the Fusion Drive had failed. The SDD was working fine, but the (mechanical) hard drive had failed. A Fusion Drive us made up of an SDD drive and a standard hard disk drive combined to look like a single drive under OS X.

Luckily I hadn’t lost any data, but wasn’t sure what to do next.

I did reformat the SDD and installed OS X onto that (and even upgraded to Big Sur). The speed was very impressive and to be honest part of me did think about leaving it like this. However this wasn’t a practical long term solution as the iMac would just randomly reboot for no reason. Certainly couldn’t use the iMac for anything productive.

I did look into fixing the iMac myself, but in the end booked it into the Cribbs Causeway Apple Store Genius Bar for an appointment. The 2014 iMac counts as vintage technology (as it is just under their seven year limit) and isn’t quite obsolete, yet!


So last week the hard drive on my iMac stopped working. I had tried to repair the drive and reinstall Mac OS X. In the end I bought a new external hard drive and decided a new approach and in my last blog post I discussed how I was using the migration assistant to copy files and settings from the defunct drive to the new external drive, and how I had to wait….

Having left my iMac overnight I came down the following morning, slightly apprehensive I looked in on the iMac, pressed the space bar, and I was rather downhearted to see the prohibitory symbol.

Mac prohibitory symbol

Oh no, this reminded me of 2017 when the fusion drive had failed.

It looked like the whole process hadn’t worked.

So I went to make coffee, but when I came back it had gone and I saw the Migration Assistant back in full flow finalising the migration. Maybe it had worked.

Once the migration process had finished I rebooted the iMac using the external drive and everything was working now.

Well not quite, though all my data was on the external hard drive, the settings needed to be updated and various applications needed passwords and all manner of things.

So my plan for the day was to work from the external hard drive and then later reformat the iMac hard drive and migrate the data back.

To be honest I got so fed up with the spinning beachball that I started the Migration Assistant just before lunch. I took the decision not to migrate some of the user accounts, as yes I wanted to retain the data, but didn’t need it on the main machine.

So I formatted the internal iMac fusion drive, checked the health of the drive and installed a fresh copy of OS X on there. I then started the Migration Assistant, taking the data and settings from the external drive and putting it back on the internal drive.

What was interesting was how much faster this process was from external hard drive to the internal drive compared to the other way round.

It was also interesting to note that once I had completed the migration, that unlike working from the external drive, as well as no spinning beachballs, most things were working just as they were before the crash.

So, so far, all seems to be working fine.

So I waited….

So last week the hard drive on my iMac stopped working. I had tried to repair the drive and reinstall Mac OS X. In the end I bought a new external hard drive and decided a new approach.

I took the decision that I would install Mac OS X on the external drive and then from there retrieve the files from the iMac hard drive.

I could then either reformat the iMac HDD and reinstall OS X or use the external drive as the main drive. Less keen on the latter option as the drive would be significantly slower than the fusion drive on the iMac.

I am hoping that it is a software issue with the drive and not a physical problem. Regardless I did want to take off the data and try a fresh install.

If that didn’t work, then it might be a trip to the Apple Genius Bar, but I didn’t fancy spending £300 on a replacement fusion drive, especially as the computer is now eight years old and having done this already before.

So I connected the drive to the iMac by the included USB-C to USB 3.0 cable and started the iMac off in recovery mode. I did try and install OS X onto the drive, but that wasn’t going to work as the default file structure on the drive when it shipped was FAT. So I started Disk Utility and formatted the drive to APFS ready for installing Mac OS X. This all worked and went to install OS X. 

This also worked and I was feeling quite pleased, however the real challenge was going to be was moving the data and documents over from the iMac hard drive to the external drive.

However I had forgotten about the Migration Assistant, a tool I had never used. Usually when I buy a new Mac I like to start from scratch and only install the apps I know I am going to use.

However this time I thought the Migration Assistant would be a better choice.

So I said yes in the OS X install screen and selected the internal iMac drive and selected all the files I wanted migrated and then waited….

As I was told it was going to take fifteen hours…

So I waited…

Got the drive

Well I collected the drive I had ordered. It is smaller than I thought it would be for a 4TB drive, well that’s nice.

I have always liked Lacie drives as they are reliable and look great. I also like the fact that they come with the cables you need. This one came with the USB-C to USB 3.0 cable I needed, and to think I nearly bought a cable, so glad I checked the details about the drive.

I did consider buying the Apple UBS-C to Thunderbolt 2 adapter, but at nearly £50 was expensive, for what would really be a single job for the speed advantage.

I then started to think about how I would extract my data and then reinstall Mac OS X on the iMac.

What should I do?

I started thinking about what I should do with my iMac now that it wouldn’t start and I couldn’t reinstall OS X onto it.

I knew I could copy files off it, so thought about whether I should start that. However that would mean using multiple drives and using another Mac. I knew that this would take time, as moving files from one mobile drive (well the iMac in disk mode) to another takes much longer than moving them from the internal HDD to an external HDD. The Mac mini I was using to connect to the iMac only had a small SDD so wasn’t an option.

In the end I decided that I would buy a new external hard drive. 

I went with the LaCie STHG4000400 External Hard Disk Drive. I went with the 4TB version in silver.

Though I went with the USB-C interface, I knew that included was a UBS-C to USB 3.0 cable I could use with the iMac.

Having ordered that with next day delivery I turned the iMac off and left it alone.

Installed Snow Leopard

I have now installed my copy of Snow Leopard. I have installed it onto an external LaCie Poulton 1TB Firewire drive for my iMac.

My current OS is Leopard 10.5 and that is also installed on a (different) LaCie Poulton 1TB Firewire drive. I am using external drives as the internal drive on the iMac was a little too small for me at 250GB – when did 250GB become too small?

So far everything seems okay and Snow Leopard appears a little snappier than 10.5.

My main concern is that EyeTV 2 is not compatible and so I will need to go out and buy EyeTV 3 which means that is not such a cheap upgrade as I would hope.

Adobe CS4 should work fine, and I already have iLife 09 and iWork 09, so no worries there.

Over the next week or so I will be installing various apps to check they work before moving over my data.

The advantage of not upgrading is that I can always fall back on my previous installation if it really doesn’t work out.


After much deleting and arching I have freed up 200GB of hard disk space.

I do consider it strange that I now view 200GB as “small” when a few years ago I considered 250MB Iomega Zip disks as “huge”.

The iMac I use the external drive with only has an internal drive of 250GB, which is why I now use an external 1TB drive as my main startup disk.

The first laptop I was given at work had a “huge” hdd, 20MB, yes MB not GB.

I am going out to buy some more external storage, I have started to look at 2TB drives… I have considered a Drobo, but am wondering about the noise, I do like my quiet Lacie Poulton 1TB drive and will probably get some more of them.

So is it faster?

I have been using my new LaCie Poulton drive for over a week now and so far I am impressed with it. Running Leopard on it for my iMac means I now have a lot more free space over 700GB compared to the 15GB I seem to have with the original 250GB hard drive I had on the iMac.

So is it faster?


It certainly appears to be faster, but I suspect that Leopard is also a factor as that made a difference with my MacBook Pro.

It was certainly a bit of a pain going through all my applications and re-installing them, re-activating some and finding the serial numbers of others.

Installing Leopard

So I have my new drive, a 1TB LaCie Poulton, and though it is not as quiet as I would like (well a 7200rpm drive is still quite noisy, but at least there are no noisy fans).

So decided to install Leopard on it and use it as a boot drive for my iMac. The iMac only came with a 250GB drive which is proving problematic, I am hoping with 1TB of space that I can at least have a little more room for “stuff”.

Rather than install Leopard direct, I decided to install from the iMac install disks and then install Leopard on top of that.

Once Tiger was installed, I went straight to Leopard. Once Leopard was installed I then ran Software Update, and of course forgot to change the energy saver settings, so as before, the iMac did a Vista on me and turned itself off whilst downloading a 560MB update – for 10.5.4

I will then need to decide which software to install that I will use.

Wondering if Office 2004 is Leopard compatible (I think it is) and wondering if CS2 is? Problem with both those is that they are both not Universal applications, so both rely on Rosetta as they are PowerPC applications, and as a result are quite memory intensive.

Will certainly be installing iWork ’08 and iLife ’08 and iMovie HD ’06 as well.

Still downloading the updates.

Quiet External Drive – LaCie Poulton 1TB

Was is only a few days ago I was blogging about noisy external drives when I happened to find myself in the Apple Store in Regent Street in London when I noticed that they had a LaCie Poulton drive on display, switched in and boy was it quiet. So quiet that even when I put my ear to it, I couldn’t hear it!

No fans.

So even though I had only popped in for a look at the Apple Store, out came the wallet and a purchase was made.

LaCie Hard Drive by Poulton