Fast Flash clean ?

[Sponge Bob]

Hi
I have a 2012 iMac with a 1TB HDD. It has 128 GB of fast flash.

I'm going to sell this and want to clean the whole drive so nothing is recoverable even from the Fast Flash.

But I will leave a factory install of the latest Sierra OS, so I just want to 'clean' the free disc space including the Fast Flash.

I know how to overwrite the freespace on the HDD using diskutil from the Terminal, but do I need another method for overwriting the Fast Flash ?

many thanks

 

[RadDave]

Hi Sponge Bob - welcome to the forum! I have an early 2013 iMac w/ the same 'fusion' drive - take a look at Apple's Support Article on the topic of selling or giving away your computer - follow all of the steps - scroll down to item #5 which has a link about erasing and reinstalling macOS - hope this helps. Dave

 

[Sponge Bob]

Hi Dave,
thanks for the reply.

There's no mention of the flash flash in the procedure so I guess there's nothing to do.

I never really understood fast flash, what it does or how it works. My bad

Bob

 

[RadDave]

Hi Dave,
thanks for the reply.

There's no mention of the flash flash in the procedure so I guess there's nothing to do.

I never really understood fast flash, what it does or how it works. My bad

Hi again Bob - for further information on the 'fusion drive' check this Apple Article - one paragraph quoted below from the link. My iMac was purchased in the spring of 2013 but is a late 2012 model, likely similar to yours - the drive functions as 'one unit' (see my System Report below - Storage selected along w/ the internal drive; the other two at the top are my TM external drives). SO, when you follow the 'erasure' instructions, both the HDD/SSD portions are handle as one. Dave

Presented as a single volume on your Mac, Fusion Drive automatically and dynamically moves frequently used files to Flash storage for quicker access, while infrequently used items move to the hard disk. As a result you'll enjoy shorter startup times, and as the system learns how you work you'll see faster application launches and quicker file access. Fusion Drive manages all this automatically in the background.

.

 

[harryb2448]

Do you have the OS on a USB thumb drive to re-install? You erase the entire rive and that will look after the Flash Storage, BUT you need to be booted from say the OS thumb drive, or an external hard drive that has been cloned to do the erase. You cannot erase a drive you are booted from, other than using Recovery Mode.

You can use Recovery, but be aware that it is a long, slow operation, at least overnight. If you have the thumb drive, boot from it, go into Utilities and there do an erase and format, install the OS and when it reaches the stage to begin the setup, simply hit Command Q for Quit. When the new owner boots, it will open at that page and they can enter all their own information and password.