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A big thank you Howard, owing to your help i'm now running my 1TB FD with dual OSX/Bootcamp booting off the SSD with 700GB of the HD in Fusion with the OSX part of the SSD, and the rest of the HDD available to Windows. Would not have managed it without this thread, so thanks again to you all!
 
A big thank you Howard, owing to your help i'm now running my 1TB FD with dual OSX/Bootcamp booting off the SSD with 700GB of the HD in Fusion with the OSX part of the SSD, and the rest of the HDD available to Windows. Would not have managed it without this thread, so thanks again to you all!

You're welcome ... I'm glad that this info may have helped you find success! :)

Enjoy your new iMac.


Merry Christmas to you and the rest of the forum... :)

-howard
 
Hi all,

I just bought a new Mac Mini, installed an SSD in addition to the 1TB HDD that came with it, as soon as I opened disk utility, it merged the drives, exactly what I didn't want...! Can't seem to find a solution anywhere to reverse the fusion of the drives, anyone have a link or some advice? I assume it is possible?

Interesting for those who want Fusion but don't want to spend $300 on the Apple one in the new Mac Mini.

Can I ask why people want to split them up?
 
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Hi all,

I just bought a new Mac Mini, installed an SSD in addition to the 1TB HDD that came with it, as soon as I opened disk utility, it merged the drives, exactly what I didn't want...! Can't seem to find a solution anywhere to reverse the fusion of the drives, anyone have a link or some advice? I assume it is possible?

Its very easy to unfuse the drives, pm me if you want me to walk you though it.
 
Interesting for those who want Fusion but don't want to spend $300 on the Apple one in the new Mac Mini.

Can I ask why people want to split them up?

When working with big files such as video im talking abunch of 10Gb video files on a single project is better not to have the os moving files from here to there. it is better for me to select for example.coded footage on the hdd an uncompresse bits and.pieces on the ssd. And so on... My imac hasnt arrived yet but unfusing the drive is one of the first things i will do.
 
When working with big files such as video I'm talking a bunch of 10Gb video files on a single project is better not to have the OS moving files from here to there. it is better for me to select for example.coded footage on the HDD an uncompressed bits and.pieces on the SSD. And so on... My iMac hasn't arrived yet but unfusing the drive is one of the first things i will do.

Fair enough but wouldn't it be better to just use an external drive via USB3 or TB?
 
From the number of postings I've seen regarding "splitting" and "re-creating" fusion drives, it's apparent that Apple was woefully negligent in introducing the "fusion concept" without an adequate utility to MANAGE fusion. They could at the very least have upgraded Disk Utility to give the end user the power to create or separate fusion drives as needed. (Aside: to those who would respond by saying "why would you need to do that?", whatever happened to "the POWER to be your best?")

I see a big opportunity for a software developer to jump into this frey with a suite of "fusion utilities" that would give an end user "full control" over creating and un-creating fused drives, partitioning the hd portion of the fusion drive, etc.
 
They could at the very least have upgraded Disk Utility...

They did upgrade Disk Utility but Apple being Apple they don't want you to tinker with Fusion.

But I do agree the ability for the end user to decide would be nice, especially those with a Mac that can easily have a 2nd HDD added like some 2011 iMac's, the Mini and Pro it would be great to be able to create a Fusion drive if needed without shelling out for the $300 upgrade from Apple.
 
http://arstechnica.com/apple/2012/1...ining-doc-ars-tears-open-apples-fusion-drive/

Follow this article, especially page 2. Boot in recovery mode, then open terminal, and type these commands:

diskutil cs list

This command will show you the IDs you need to delete fusion drive.

diskutil cs deleteVolume < insert fusion logical volume ID here >
diskutil cs delete < insert coreStorage logical volume group ID here >


These commands will split the drives apart. Once the drives are separated, you can rename those drives in Terminal, because you can't use Disk Utility: it will try to fix the Fusion Drive for you.

diskutil list

This command will show you the identifier for the two drives, that you'll use this way:

diskutil rename disk0s2 Macintosh HD
diskutil rename disk1s2 Data HD

Exit terminal, click on "Install OS X" and select the SSD, and you're good to go. Once in disk utility in OSX, the drives will be listed normally.


I'm receiving my imac today. Can somebody confirm these steps?
 
When working with big files such as video im talking abunch of 10Gb video files on a single project is better not to have the os moving files from here to there. it is better for me to select for example.coded footage on the hdd an uncompresse bits and.pieces on the ssd. And so on... My imac hasnt arrived yet but unfusing the drive is one of the first things i will do.

ok so i do audio not video, im a little concern after splitting fusion drive, that I might full the SSD pretty soon with applications and files/libraries that have to be on the disk where your OS is installed. how you gonna deal with this ?:confused:
 
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ok so i do audio not video, im a little concern after splitting fusion drive, that I might full the SSD pretty soon with applications and files/libraries that have to be on the disk where your OS is installed. how you gonna deal with this ?:confused:

I do video and after installing all my apps I still have 97GB free on the SSD. A big benefit for un-fusing is that you can use the spinning disk for scratch and SSD for osx / applications. Footage on external thunderbolt. This machine is raging with Davinci Resolve!
 
I do video and after installing all my apps I still have 97GB free on the SSD. A big benefit for un-fusing is that you can use the spinning disk for scratch and SSD for osx / applications. Footage on external thunderbolt. This machine is raging with Davinci Resolve!

Thats great to know I was worried about filling the SSD with my apps but not anymore!

Quick question, what do you mean by "use the HDD for scratch"?
 
I was going to do this and then it occurred to me.... why not partition the hard drive to the smallest space possible for the OSX partition.

That way I can control what is on the SSD and the normal HDD without having to disable it. So I can still keep the speed of the fusion drive.

Please correct me if you read this and my logic is wrong as I thought it was worth a try.

I partitioned the drive into a 200GB and 800GB sections.

I did try to partition it to 124GB but OSX wouldn't let me.

What that did was leave me with 60GB on the HDD plus the 128GB SSD and all the rest of the HDD as the other partition.

I then moved my iTunes library to the HDD so the combined usage on my fusion drive/HDD is only 90GB leaving everything on the SSD that I would use most of the time, and in theory the HDD will only be used when I'm watching media which then won't bother me with extra noise as I'll have the speakers on but in normal browsing it should be totally silent...plus I still get the smart caching of files as the fusion is still operating and has some normal HDD space available.

Does that make sense?
 
Hey guys I need some help! This will likely take some smart thinking to fix. :(

I got a fusion iMac today. I've installed OS X on a Thunderbolt SSD, and I wanted to install Windows on the Fusion disk, but on the SSD portion.

So, I have OS X running just fine on the external SSD.
I have the fusion 1.1TB disk separated, and have successfully installed Windows 7 on just the SSD. Now, I separated the remaining 1TB drive into two partitions, one for OS X, and one in NTS for Windows.

I have no issues in Bootcamp and can see that 500GB NTFS partition no problem.

However, I run Parallels in OS X but cannot access the NTFS portion of the 1TB drive in Parallels. I wanted to unmount the NTFS disk in OS X and then mount it in Windows 7 in Parallels, but after ejecting the disk I can't re-mount it because of course Disk Utility wants to "fix" the fusion drive.

Is there a way to get this NTFS portion of the 1TB disk to connect in Parallels in some way? I really need to be able to read AND write to it in Parallels! Gah!

ANY help appreciated!

Thank you!
 
Hey guys I need some help! This will likely take some smart thinking to fix. :(

I got a fusion iMac today. I've installed OS X on a Thunderbolt SSD, and I wanted to install Windows on the Fusion disk, but on the SSD portion.

So, I have OS X running just fine on the external SSD.
I have the fusion 1.1TB disk separated, and have successfully installed Windows 7 on just the SSD. Now, I separated the remaining 1TB drive into two partitions, one for OS X, and one in NTS for Windows.

I have no issues in Bootcamp and can see that 500GB NTFS partition no problem.

However, I run Parallels in OS X but cannot access the NTFS portion of the 1TB drive in Parallels. I wanted to unmount the NTFS disk in OS X and then mount it in Windows 7 in Parallels, but after ejecting the disk I can't re-mount it because of course Disk Utility wants to "fix" the fusion drive.

Is there a way to get this NTFS portion of the 1TB disk to connect in Parallels in some way? I really need to be able to read AND write to it in Parallels! Gah!

ANY help appreciated!

Thank you!

When running Windows under Parallels, all of your I/O is actually going through OS X, so you can't normally write to NTFS drives. You can get NTFS drivers for OS X which will allow writing to the NTFS partition, or create a FAT32 or ExFat partition to share your data on.

-howard
 
When running Windows under Parallels, all of your I/O is actually going through OS X, so you can't normally write to NTFS drives. You can get NTFS drivers for OS X which will allow writing to the NTFS partition, or create a FAT32 or ExFat partition to share your data on.

-howard

So boot into Windows 7 via Boot Camp, and then reformat the disk as an ExFat disk? I can't do anything with it in OS X it seems, since it's red in Disk Utility and all Disk Utility wants to do is recreate the fusion disk.

Thanks...
 
OK so I can't figure out how to reformat to ExFat. I can't do it in Disk Utility since it's not letting me (just wants to fix the fusion disk), and I can't seem to do it in Windows since Format only gives me the NTFS option.

Any other ideas? Thanks.

*EDIT*

Managed to format the drive via the command prompt in Windows 7. It's never easy...

FYI, this command did it:

FORMAT E: /FS:exFAT /q

(where "E:" is your drive letter.)

As a side-note, is there a way to password protect Disk Utility? I'm TERRIFIED someone will click on one of the disks in red, and hit FIX. At which point I'll lose my photos, my Windows 7 installation, and all my games (on the ExFAT drive). That's a lot to lose in one click!
 
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lol my Disk Utility is a total mess right now. It's really funny actually. :D

Be nice if I could use Disk Utility on the fusion "array" to check it for errors, but that's obviously not going to be possible right now.
 

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Hi WilliamG...

I believe you can use Terminal "Diskutil" commands to do anything that Disk Utility would do for the things you mentioned above. The Terminal will not try to force a Fusion re-join as Disk Utility seems to do (Apple needs to stop that action in the next public release).

Here is some documentation about "DiskUtil" you may want to look over, you can also get brief help from within terminal by just typing the command with no options and it will show you what options are available.

DiskUtil Manual Page from Mac Developer Library:

http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man8/diskutil.8
 
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