Is anything written permanently to the Fusion Drive's SSD?

Is anything written permanently to the Fusion Drive's SSD or is it just a very large cache for the HD component?
I'm wondering, because I'd like to know, mostly out of curiosity, if the mechanical portion of the Fusion Drive were to fail, might the computer still boot from information on the SSD?

(I back it up with Carbon Copy Cloner AND Time Machine.)
So, if either part fails, the machine is quite dead until the internal drive is replaced? I ask because these two drives are detected separately in utilities such as TechTools Pro, where their S.M.A.R.T. data can be retrieved and tested independently.
If a failure of either portion of the drive totally disables the whole drive, would this sort of double the chance of a Fusion drive's failure?

Similar Messages

Can't back-up new iMac with fusion HD. The back-up proceeds to within 10% of the total storage needed and then the "of" number increases. I suspect there is a problem with backing up the fusion drive. We have a new 3 TB time Capsule. Any ideas?

Can't back-up new iMac with fusion HD. The back-up proceeds to within 10% of the total storage needed and then the "of" number increases. I suspect there is a problem with backing up the fusion drive. We have a new 3 TB time Capsule. I tried excluding different parts of the software from the back-up but it didn't make any difference. I even tried exluding "invisible items" to no avail. Any ideas?

When you setup the wireless and ethernet in the computer.. ipv6 will be on automatic.. this is wrong for the latest TC firmware and airport utility. http://support.apple.com/kb/TS4597
Go to the wireless and ethernet setup in preferences and change ipv6 to link local.
Once you do the big backup by ethernet the wireless will function fine for incremental.. it is obviously not estimating the size correctly..
A full back-up on the iMac would be about 650 GB. The partial updates that I have been trying start out at 115MB and keep growing indefinitely. The original back-up never finished nor have any of the follow-up attempts.
The first estimate should be the full backup but it will keep growing as the backup advances.. I would also delete any inprogress files to make sure it is not messing up .. delete even a sparsebundle if there is one for the imac on the TC and start afresh once you have ethernet connection.
See A10 here.
Pondini may have some other clues there to give you an idea of why the backup is slow or not finishing.. there is a lot of issues with TM when it decides not to work.

If I install Windows 7 on iMac (what we have done many times and it works very good) does windows support the fusion drive?

if I install Windows 7 on iMac (what we have done many times and it works very good) does windows support the fusion drive?

Welcome to the Apple Support Communities
Fusion Drive is created by software on OS X. On a computer with Fusion Drive, Windows is installed on the HDD, but when you install the Boot Camp drivers, you will be able to read Macintosh HD, so it looks like it supports Fusion Drive but only for read

Is Disk Utility in OS X 10.8.2 the version of Disk utilit that controls the Fusion Drive on new Imacs?

is Disk Utility in OS X 10.8.2 the version of Disk utilit that controls the Fusion Drive on new Imacs?

No. Only those computers with a Fusion Drive installed will get the special version of Disk Utility. Do a Google search if you want to find out how to create a fusion drive with older systems, but I suggest it's a waste of time.

We are getting ready to purchase the new iMac 27" and would like to know which is best for watching streaming video, the fusion drive or the more expensive flash drive only

We are getting ready to purchase the new imac 27" and would like to know which is the best configuration for watching streaming video, the fusion drive or the more expensive flash drive. We will have a fast fiberoptic internet connection.

the harddisk speed mean nothing when it comes to streaming video from the internet
even the fastests internet using fiberoptics is still much slower then the slowests harddisk you can buy

I just bought the new IMAC with the Fusion Drive 3t. Can I use the Bootcamp systemwith it? If not what do you suggest? I relly need the bootcamp for quicken

Good morning,
I just bought the new IMAC with the Fusion drive 3T. Can I use it with bootcamp beacuse I need for Quicken?If not any suugestion?

You can't use Boot Camp in 3 TB drives. You can download VirtualBox, Parallels or VMware Fusion and install Windows on a virtual machine. See > https://discussions.apple.com/docs/DOC-3321

Can the hdd part of the fusion drive be replaced with a large sata ssd?

Is there any technical reason why the mechanical (hdd) can't be replaced with a large sata ssd in the fusion drive setup?

None of these replies addressed the reason for my original question.
I do appreciate the answers however I see I should have been a bit more thorough in my query.
I know how the fusion works. I know you can get a 1 tb ssd with the imac.
I also know that it is very very expensive to get a pure pcie 1 tb ssd as an option.
The reason for my question is to see if the sata ssd which is a little slower and also much much cheaper than pcie flash ssds can be used instead of the slow
hdd in the fusion configuration. I have ordered the 512 gb pcie flash for my imac so I am committed to pure ssd. I would still like to know if
what I mentioned is possible as a much less expensive option.
Sorry for the confusion but in a rather lengthy search throughout the net and asking Apple's Geniuses I have been as yet unable to get any answer.
It would seem to me that using a sata ssd instead of a sata hdd would be nothing but beneficial in the fusion setup.

HT3476 Fusion drive versus ssd drive issues

HHow can I compare the fusion drive to the ssd drive in the MAC mini

Lanny wrote:
A fusion drive will be a little faster than a HDD and a SSD will be a lot faster than both, especially if it's connected via PCExpress 2.
I agree with the second half of your statement but my experience with the fusion drive VS a standard 5400 RPM HHD is that it is significantly faster, not a little. Apple has managed to find a good balance between permanently storing often used items on the SSD and using it for buffering.

Fusion Drive 4TB + SSD m4 512 Go DEAD can't reformat

Hello,
I have an iMac 27 late 2010 i5 3.6 with 16 Go of RAM running 10.8.3
For Christmas, I received a M4 SSD 512 Go and decided to replace the 2TB in my iMac with a 4TB and create a Fusion Drive.
The operation worked beautifully and my iMac became incredibly fast, which was the goal.
Yesterday, the iMac did not start and I got the white screen with the spinning wheel. After reading about zapping the pram and Vram, nothing worked.
I booted from an external hard drive with Mac os X 10.8.2 and ran Disk Util to check the drive. I got a lot of red lines in the report and got the error Disk Utility can't repair this disk. back , reformat and restore.
I was able to copy some of the files on the drive and decided to reformat the drive.
Everytime I try to reformat the drive (4.4tB Fusion Drive) the mac shuts down and restarts.
I tried to un fuse the fusion drive and I get the same result. the screen goes black, the computer restarts and displays that the mac encountered a problem and had to restart.
when I type the commande in terminal diskutil cs file, I see the logical volume group.
When I do a diskutil cs Delete Volume xxxxxx xxxx xxx x x x x x x x
started CoreStorage operation on disk 2 iMac
Unmounting disk2
Removing Logical Volume from Logical Volume Group
then the mac shuts down and restarts.
it took me 2 hours to crack the beast open to perform the disk implant last christmas and it was scary. I thought I would never manage to close it properly.
I understand that this operation voided the warranty (i have the Apple Care for 3 years).
Any help greatly appreciated.
Thanks
Phil

Thanks for your answers.
I still don't know if it was the SSD or the HD that was faulty but I found a solution via this post
https://discussions.apple.com/message/21492423#21492423
Jerome Tremblay
This solved my questionRe: Unable to reformat/repartition Fusion Drive
Mar 12, 2013 11:05 AM (in response to Topher Kessler)
@Topher : It did not work, and it failed with POSIX errors similar to the zeroDisk message I posted above.
However, While I was unable to "cleanly" solve my problem, I managed to reset everything by booting in single-user mode from an external hard drive (with cmd-S) and overwriting the disk directly with
cat /dev/random > /dev/disk0 cat /dev/random > /dev/disk1
Then I rebooted and I could reformat the drives (actually, I created another fusion drive using these directives).
I was able to reformat the drives as a Fusion Drive. My time Machine backup was only a week old but it worked perfectly. I was able to add the rest via my Backblaze subscription.
Don't know how long the Fusion drive will last but I am prepared with my backups in case it happens.
Phil

Fusion drive vs ssd 256gb which is better

hoi gang, im in the market for a new mac mini. and i need some help with choosing the right options when buying it.
" i do music " and i need a mini that fast and runs at the highest possible speed when making music. and of course using it for some fotos, emails and yes internet.
so ....
specs im choosing
2.6 ghz
16GB 1600MHz DDR3 SDRAM - 2x8GB
Now here is my problem which one do i choose?
1TB Fusion Drive [Add $250.00]
or
256GB Solid State Drive [Add $300.00]
Remember i need the mac that is the best at everything and speed is important!!!

Choose the 256 GB SSD disk if you need more speed. Fusion Drive is a small flash drive and a hard disk that work together, so OS X automatically puts your most used apps and documents on the flash storage.
If you need storage, you can choose the Fusion Drive or the SSD and an external disk

Is it possible to delete the fusion drives' standard partitions to be able to use the SSD part only for the OS?

Like the question suggests, I'm thinking about purchasing one of the new 27'' iMacs and I'm wondering if I'd be possible to repartition the 3TB fusion drive to use the 128GB SSD part only for the OS.

Thanks a lot for this fast and helpful reply!
€dit: I accidentially clicked on "This helped me" instead of "This solved my question" and now it seems like I'm unable to change that :/

Larger Flash in the Fusion drive

I want a new iMac for music composition and would like a 1 or 3GB fusion drive with the flash portion of 512GB. Is this possible and if not, can I have two SSDs fitted?

iMacs only come with a single internal drive. A second drive cannot be installed; there's no room. Apple's Fusion drive comes 1TB or 3TB with a 128GB SSD integrated. You cannot order a Fusion drive with a larger SSD partition. You can only order a single SSD-only internal drive up to 1TB. That's it.
iMacs come with 2 Thunderbolt ports and 4 USB3 ports that can support expremely fast external drives, as many as you want, any size you want.

How to clean-install Mavericks to a fusion drive?

Because I cannot find a complete answer here or anywhere else, I seek information about reinstalling Mavericks on a 1TB fusion drive on my late 2013 iMac. I see discussions about reinstalling, backing up data, Boot Camp issues, rebuilding a fusion drive, making a fusion drive from scratch, and the like; but I do not find the level of detail I am seeking about starting over with a fusion drive. I upgraded to Mavericks from Mtn Lion and now see hints that I needed to do something special to take advantage of the properties of this drive.
That said, here are my questions:
(1) When I "Command-R" reboot to Recovery and get to the Disk Utility, I see a separate 1TB HD as an extended partition as well as a 125GB drive that is root (/), which I presume is the SSD. To accomplish the clean installation, do I format BOTH? Or will formatting only the 1TB HD suffice? Does formatting only the 1TB HD also take care of formatting the SSD? Maybe it's not advisable to format the SSD ...?
(2) Does the downloaded Mavericks installer loaded onto a USB stick using DiskMakerX have the capability to do this clean install properly? or is it necessary, in order to take advantage of the fusion drive properties (SSD+HD), to download Mavericks Installer after wiping the HD so that support for the fusion drive is maintained?
(3) Because I am curious, where does OS X (I mean the OS, not data) reside after the installation is done? on the SSD? on the HD? I ask this because I have read that "the OS remains on the SSD," but, seemingly in conflict, that the SSD is for quick access to frequently used programs and data. Both could be correct.
Sorry for the length of this. And thanks.

The screenshot of DU within the booted Mavericks, not Recovery.
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage                         121.0 GB   disk0s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:          Apple_CoreStorage                         999.3 GB   disk1s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           *1.1 TB     disk2
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk3
   1:                        EFI EFI                     209.7 MB   disk3s1
   2:                  Apple_HFS LaCie                   499.1 GB   disk3s2
   3:                 Apple_Boot Recovery HD             784.2 MB   disk3s3
And you know what this is, per your request. It shows the OS on the SSD portion, the Recovery partition on the HD, etc. It's a little confusing because the disk reference numbers do not agree with those in the screenshot below, but that probably is because the shot below results from booting from a USB stick.
Now to your comments/answers/thoughts:
(1) Issue of number of drives. This is a fuzzy iPhone screenshot of DU after booting from a USB Mavericks installation stick:
Looks like I cannot format the SSD directly, if that is what disk5 really is. Below I mention another possibility for getting it formatted (third paragraph from the end).
(2) Which source for new installation of Mavericks
I agree that it's probably best not to use the USB stick I have but to use the Recovery method to download a fresh copy. I'm not sure about the reliability of the USB vs downloading, either, but there is some evidence out there (somewhere -- I've seen it but I don't recall where) suggesting it.
(3) Where OS X is installed -- fusion drive portion or HD portion of the Macintosh HD:
From the information given with "disk5" in the screen shot just above, it does appear that after a USB boot, DU sees items separately, including the main storage (Macintosh HD), the Recovery partition (disk4-used also for creating the USB stick installer), and OS (disk5). Some of this layout may hold true with a "Command-R" boot from the Recovery partition, and I know I've looked at it but for the moment cannot recall the information.
Further, it appears the OS is on the SSD. It also appears it cannot be formatted UNLESS such formatting occurs when the target for the formatting process is "Macintosh HD." I am inclined to believe now that when I make this clean reinstallation, the new copy of OS X will be put on the SSD portion, as you state. I am aware that the moving of data back and forth from SSD to HD is outside user control.
Lowluster, thank you for answering my questions in such an organized fashion (that I can follow!). I feel confident now about proceeding even though not all questions are answered definitively.
Allan, I'm glad to know about fusing separately an SSD with an HD. It will be useful should I run into another user's desire to create a fusion drive. Thank you again.
David

After attempting secure erase, iMac w/homemade fusion drive won't boot from *anything*

2009 iMac with homemade fusion drive (SSD installed in optical bay). Was working fine with Yosemite until I attempted to secure erase it before giving away the machine.
Now the drive is borked. Disk utility could make no sense of it, can't reformat, it can't repartition it. And now it has completely stopped booting. I cannot even get it to boot of an external USB drive anymore (the original operation was performed while booted from a Yosemite installer drive on a USB stick).
I've reset the PRAM, reset the SMC, and just nothing. All boots are attempted from internal messed up fusion drive, which eventually ends in the "prohibitory sign".
I'm not even sure what to try at this point. Any suggestions out there?

Thank you for the reply. I have since resolved the problem, although not in the most satisfactory way.
Here's what I did:
Pulled both drives out of the iMac, put them into a USB dock, and reformatted each one. Both drives appeared at this point to be fine.
Reinstalled both drive into the iMac, and started up from a USB drive. No problem.
Recreated the fusion drive from the terminal. No problem.
Now, because I am a glutton for punishment, I tried wiping the fusion drive again. This time, part way in, it kernel panicked. Luckily, I was able to reboot once again to the external drive.
At this point, the fusion drive was in the exact same messed up state as when I started. Disk Utility app could do nothing with it.
Fortunately, this time I went right to the command line, and was able to fix things up and recreate the fusion drive before anything else bad happened.
I gave up on wiping the drive for now. If I need to do so in the future, I will disable the fusion drive and try to wipe each physical drive separately.
I should note that this iMac has never given a spot of trouble before now, so I am highly suspicious of the way disk utility tries to wipe a fusion drive. I certainly won't try it again. (I don't know if it has ever kernel-panicked before in the 5 years I've owned it).

Mac Fusion drive: The disk "Macintosh HD" could not be unmounted

Hi
I recently purchased a Mac Mini with the fusion drive. When I perform a verify and repair of the disk, I get the error "The disk Macintosh HD could not be unmounted". This does not occur with any of my other computers, imac or powermac (also running mountain lion). So I am wondering if I have a defective Fusion/HD or if this is simply a peculiarity of the fusion drive itself. Please comment.

If your Fusion drive can be repaired with Disk Utility, it will be shown with red lettering. If you are not seeing red lettering, then you need to boot into Recovery mode to use that Disk Utility. When you order a Fusion drive equipped Mac, there is a special version of Disk Utility included in OS X specifically for operation with Fusion Drives.
If you have any open files on the volume you wish to verify/repair, then Disk Utility will throw its hands up and give you that cannot unmount drive message. Make sure you have quit all applications you were using that may be accessing files on the disk in question.
Apple article.

Is anything written permanently to the Fusion Drive's SSD?

Similar Messages

Maybe you are looking for