Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

hfg

macrumors 68040
Dec 1, 2006
3,621
312
Cedar Rapids, IA. USA
My thoughts exactly. Fusion drive is the equivalent of RAID 0, which effectively doubles the failure rate. I would've much preferred a RAID 1 style implementation (in the sense of the flash space being a duplicate rather than the only version of the data), providing redundancy and therefore allowing for SSD failure.

So, where does that leave you if it is the Fusion hard disk that fails?

The SSD will have bits and pieces of files and may boot, but not much more.

Even if you only have one disk in your system, if it fails ... it is toast.

Everyone needs to have a good backup solution, no matter what drives you have in your computer.

Although there is a lot of talk about disk failures here, I don't really think that many users actually have a disk failure during the useful life of the equipment. Sure, there will be a few who will tell of their failure ... but that is why we all should keep a backup in case we are the "isolated case" who actually experiences it.
 

jowie

macrumors 6502a
Jun 9, 2004
571
8
London ish
I agree that there is no excuse for not having a decent backup plan. I realise that sealed units is the way Mac disk storage is going now, but I'd be interested to find out what happens if you try to take the HD out and stick it in a USB case... Is it even readable? If it is, since Fusion Drive keeps all the most used files in the flash storage, I assume that the HD will just be full of the less important files...
 

hfg

macrumors 68040
Dec 1, 2006
3,621
312
Cedar Rapids, IA. USA
I agree that there is no excuse for not having a decent backup plan. I realise that sealed units is the way Mac disk storage is going now, but I'd be interested to find out what happens if you try to take the HD out and stick it in a USB case... Is it even readable? If it is, since Fusion Drive keeps all the most used files in the flash storage, I assume that the HD will just be full of the less important files...

Neither drive is useable by itself. The disk management is not by files, it is by blocks (small chunks of files), so in some cases only the frequently accessed parts of files will be on the SSD, or only portions of a packaged file set will be on one drive or the other. You can't tell and really don't need to know. :)

You can't analyze what is on which drive in a Fusion environment ... you simply need to accept it as a single drive and use it as such.
 

gnasher729

Suspended
Nov 25, 2005
17,980
5,565
My thoughts exactly. Fusion drive is the equivalent of RAID 0, which effectively doubles the failure rate. I would've much preferred a RAID 1 style implementation (in the sense of the flash space being a duplicate rather than the only version of the data), providing redundancy and therefore allowing for SSD failure.

What makes you think the failure rate is doubled? The SSD drive will contain all the directories and small files, which on a hard drive would case lots of head movement and stress to the drive, so the worst stress for the hard drive is gone. On the other hand, the hard drive can contain lots of large files, and writing large files is what wears out SSD drive, so the hard drive takes stress away from the SSD drive. Each drive takes the worst stress off the other drive, so they should both last longer.
 

Planky

macrumors regular
May 24, 2009
154
31
The Sunny Isle of Wight
I am having trouble installing the system on my Fusion Drive.

I have successfully created a fusion drive by following the instructions but when I try and install Mountain Lion on it it fails with a restart and try again error.

If I try restore from Time Machine backup it starts then ends with a message "An error occurred while adding a recovery system to the destination disk".

I can happily copy to/from the fusion drive and it appears in Disk Utility and has no errors.

Any ideas?

thanks
 

hfg

macrumors 68040
Dec 1, 2006
3,621
312
Cedar Rapids, IA. USA
I am having trouble installing the system on my Fusion Drive.

I have successfully created a fusion drive by following the instructions but when I try and install Mountain Lion on it it fails with a restart and try again error.

If I try restore from Time Machine backup it starts then ends with a message "An error occurred while adding a recovery system to the destination disk".

I can happily copy to/from the fusion drive and it appears in Disk Utility and has no errors.

Any ideas?

thanks



You might post the results from the following 2 terminal commands:

diskutil list

diskutil cs list



Just for example, here is one of my MacBook Pro:
It is a little more complex than most since the 512GB SSD contains both OS X Fusion and Windows-8 boot as well as a Recovery Partition ...
and the 750GB Hard Disk contains the rest of the Fusion drive and a spare partition for Windows data (or OS X static non-Fusion storage).

-howard

.

Code:
[COLOR="SeaGreen"]Last login: Thu Jan  3 23:28:17 on console
[COLOR="Blue"]Howards-MacBookPro:~ howard$ diskutil list
[/COLOR]/dev/disk0
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *512.1 GB   disk0
  1:                        EFI                         209.7 MB   disk0s1
  2:          Apple_CoreStorage                         411.0 GB   disk0s2
  3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
  4:       Microsoft Basic Data Windows_8               100.2 GB   disk0s4
/dev/disk1
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *750.2 GB   disk1
  1:                        EFI                         209.7 MB   disk1s1
  2:          Apple_CoreStorage                         545.4 GB   disk1s2
  3:                 Apple_Boot Boot OS X               134.2 MB   disk1s3
  4:                  Apple_HFS WinData                 204.3 GB   disk1s4
/dev/disk2
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:                  Apple_HFS Macintosh Fusion       *952.4 GB   disk2

[COLOR="Blue"]Howards-MacBookPro:~ howard$ diskutil cs list
[/COLOR]CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 05DC9A0B-FFA4-492B-85D4-429CDCC083CB
   =========================================================
   Name:         Fusion
   Size:         956415746048 B (956.4 GB)
   Free Space:   0 B (0 B)
   |
   +-< Physical Volume 971AFB8A-BCB8-48C4-A689-54DE849D8E8F
   |   ----------------------------------------------------
   |   Index:    0
   |   Disk:     disk0s2
   |   Status:   Online
   |   Size:     411000012800 B (411.0 GB)
   |
   +-< Physical Volume 1159D4BD-782A-468F-AB5A-74FDF821CC6B
   |   ----------------------------------------------------
   |   Index:    1
   |   Disk:     disk1s2
   |   Status:   Online
   |   Size:     545415733248 B (545.4 GB)
   |
   +-> Logical Volume Family 5E78F881-EF15-49B0-914F-51E840A5937D
       ----------------------------------------------------------
       Encryption Status:       Unlocked
       Encryption Type:         None
       Conversion Status:       NoConversion
       Conversion Direction:    -none-
       Has Encrypted Extents:   No
       Fully Secure:            No
       Passphrase Required:     No
       |
       +-> Logical Volume D7BCE319-CF7D-4CFD-BD55-E7ADFE601E3D
           ---------------------------------------------------
           Disk:               disk2
           Status:             Online
           Size (Total):       952427741184 B (952.4 GB)
           Size (Converted):   -none-
           Revertible:         No
           LV Name:            Macintosh Fusion
           Volume Name:        Macintosh Fusion
           Content Hint:       Apple_HFS
Howards-MacBookPro:~ howard$[/COLOR]
 
Last edited:

gdourado

macrumors 6502
Apr 22, 2010
468
66
Hello,
I was reading about the DIY fusion and There is something I don't understand.

Suppose I put an SSD on an optibay on my MacBook and have an HDD on the regular slot.

I then access mountain lion recovery, write two or three commands on terminal and my fusion drive is created.

What I don't understand is that never in those commands I tell my system what drive is the SSD and what is the hdd. The SSD can either be device 1 or 3...
How does the system know?
And then, how will it swap files between the two drives?

Cheers
 

Captdaverobinso

macrumors newbie
Jan 6, 2013
3
0
Fusion Drive or Dual Drive Combo

I have seen a lot of articles on how to make a DIY fusion drive and how it initially performs but I have a couple of questions:

I have a crucial m4 128 gb SSD which I am planning to install in my late 2011 iMac. My current system is around 80 gb including iTunes and iPhoto libraries, but excluding movies which I keep on a separate drive for streaming around the house. I do some photography but do not envisage a heavy work flow for this.

Would I be better creating a Fusion Drive to simplify the system or installing the SSD as a boot drive and use the HDD for media files and documents?

I understand that apparently it is possible to use ZFS instead of HFS+ on Fusion Drives now but as I have been using HFS+ on the HDDs of my previous Macs I don not know if this is worth it?

I have also read that on SSDs alone, performance degrades as the space is filled up. I understand that Fusion Drives only keep 4 gb free before starting to fill the HDD so does this degradation in performance occur on Fusion Drives?

Many thanks

Dave
 

gdescamps

macrumors newbie
Jan 15, 2013
1
0
Could someone please tell me what I'm doing wrong in setting this up? I've got a 2011 MBP with a Samsung 830 256Gb on the main drive bay (6gbps) and a Seagate XT 750 installed in the optical bay (3gbps). I'm booting 10.8.2 from a USB stick and entering terminal where I get the bash prompt (I don't know how to get the TIN> prompt, is this part of the problem?) At the prompt, I type:

"diskutil cs create MacHD disk0 disk1"

All seems to go well, except when I enter disk utility I cannot format the newly created volume (because its "locked"), so if I go back to terminal and enter:

"Diskutil cs list"

I see my volume and associated ID. I figure it needs to be formatted, so I follow the next part of the guide and type:

"Diskutil coreStorage createVolume (UUID) jhfs+ "Mac HD" 990g"

I get a error "-69780: Unable to create a new CoreStorage Logical Volume"

After that, my SSD drive disappears and I can no longer even boot from my USB stick! The only way to recover is to take out the hard drives and reformat them in another computer! Ugh!

What am I doing wrong?

Hi Ned, I had exactly the same issue on a 2011 MBP with SSD OCZ Vector 256GB + Seagate Momentus 750GB (not XT version) installed in a data doubler.

After the error occurs (-69780) it's not possible to delete the volume (diskutil cs delete UUID), delete operation stop at 30%.
I had to delete first SSD's partitions from PC (windows 7) and then (diskutil cs delete UUID) can be done properly on the mbp!
I attempt many different size 1t, 500g, 900g, 1000g, 100% results is still the same (-69780).

I decided to not upgrade to fusion drive this time, not mature enough.
 

Cozmo85

macrumors regular
Oct 2, 2007
211
0
Hello,
I was reading about the DIY fusion and There is something I don't understand.

Suppose I put an SSD on an optibay on my MacBook and have an HDD on the regular slot.

I then access mountain lion recovery, write two or three commands on terminal and my fusion drive is created.

What I don't understand is that never in those commands I tell my system what drive is the SSD and what is the hdd. The SSD can either be device 1 or 3...
How does the system know?
And then, how will it swap files between the two drives?

Cheers

Modern OS's know what ssd's are and identify them as such.
 

aleksander

macrumors regular
Feb 26, 2008
133
153
London, UK
Macbook Pro 15" Early 2011 error

Exactly the same problem (error 69780) with FUD as all the examples above in Early 2011 MBPs. Lost 4 hours already. Must be hardware related on this particular model only. Shame :/

I think I'll leave two separate drives for now, with boot volume on the SSD. Hopefully some firmware update will resolve this...
 

Cappy

macrumors 6502
May 29, 2002
394
7
Exactly the same problem (error 69780) with FUD as all the examples above in Early 2011 MBPs. Lost 4 hours already. Must be hardware related on this particular model only. Shame :/

I think I'll leave two separate drives for now, with boot volume on the SSD. Hopefully some firmware update will resolve this...

I don't have time to read through all of the posts to see what the details are behind this but just after the fusion feature was announced with the latest imac unveiling I spoke with an engineer from Apple about it. He told me that fusion was never intended for laptops due to power saving requirements.

Unless Apple changes their mind and I would have my doubts that this ever gets addressed by anyone on Apple's side of the fence. Now if in the posts above people are finding this to be dependent on specific drives then someone might get lucky.
 

madmaxmedia

macrumors 68030
Dec 17, 2003
2,932
42
Los Angeles, CA
I don't have time to read through all of the posts to see what the details are behind this but just after the fusion feature was announced with the latest imac unveiling I spoke with an engineer from Apple about it. He told me that fusion was never intended for laptops due to power saving requirements.

Unless Apple changes their mind and I would have my doubts that this ever gets addressed by anyone on Apple's side of the fence. Now if in the posts above people are finding this to be dependent on specific drives then someone might get lucky.

I guess with Fusion Drive you could have a lot of writing back and forth between the 2 drives...
 

bradmurray

macrumors newbie
Sep 2, 2009
6
0
I spent a good chunk of my day yesterday trying to get this working on my early 2011 MBP 2.0Ghz (256GBSSD + 500GBHD). I wish I had seen this forum first because I had done a lot of reading on Fusion and I had not idea that this particular model was a problem and I had already done it successfully on 3 other MBPs (different models obviously). Fortunately I was all backed up, but unfortunately I am still mid-restore. I'm hoping 10.8.3 fixes this problem.

----------

I guess with Fusion Drive you could have a lot of writing back and forth between the 2 drives...

Only if you are doing a lot of requesting of the parts of files that are on the HD which are usually files that are not accessed very often.
 

Nathe

macrumors member
Feb 25, 2011
50
2
Staffordshire, UK
So does anyone know for sure if this works on anything other than a recent Mac Mini or iMac as OWC state? Have seen some claiming it works, others claiming it will just act as one 'dumb' volume with no migration of the most accessed data to the SSD?
 

milo

macrumors 604
Sep 23, 2003
6,891
522
Totally works on a number of macs, quite a few users have tried it and confirmed that the data is moved around as it is used more often. It's possible that some people have set it up wrong or have particular issues with their system, but in general it's working.
 

MiltonThales

macrumors member
Jan 12, 2008
46
22
Suwanee, GA
May use Partitions instead of disks

I created a Fusion drive on my 2011 iMac: I had already used an OWC DIY kit to install an SSD drive behind the optical drive in the iMac. What I found inadvertently is that the coreStorage command allows you to reference partitions, as disk0s3 and disk1s2, instead of the entire disks. I still have system restore partitions on both the SSD and the hard drive, but the coreStorage command still created the Fusion drive over the two partitions. It has worked great, with no problems -- other than consolidating the data on 2 drives into 1. That was a pain. But worth it.

I believe this true because the coreStorage command manual says the verbs require devices, which can resolve to individual partitions.
 

akasaka

macrumors newbie
Mar 7, 2013
1
0
Working fine on an early 2008 Macbook Pro 4.1

I put a 256GB Crucial M4 SSD into the HDD bay and moved the 750GB WD Scorpio Blue into the optical bay via a caddy from Ebay for about $15.

booted to the HDD in the optical bay and cloned the HDD onto an external drive connected via firewire. Then restarted and booted to the external drive. Initialised and partitioned the SSD and then used Carbon Copy Cloner to create a Recovery HD on the SSD. Built the fusion volume using the Apple_HFS partition on the SSD and all of the HDD and then copied the original OS back from the external drive. changed the startup drive back to the internal fusion volume in system preferences and restarted.

It sleeps fine, the HDD spins down, but still wakes almost instantaneously and now silently when needed. The Recovery HD is available if needed as are the options to encrypt the drive with FileVault and turn on "Find My Mac", both of which I think rely on having a recover partition.

Everything is running much much faster. Gone from being frustratingly slow recently to pleasantly fast. About 8 seconds from boot to password prompt. Also replaced one of the 2GB memory modules with a 4Gb module so it now has 6GB total, which translates to Windows 7 running happily under Parallels without having to fight for memory.

A mistake I made before doing the above was trying to do it with a 7mm Plextor M5Pro Xtreme SSD, thinking 7mm would be fine in the 9.5mm bay.. Well, the drive was fine, but the sata connector sat a touch higher, which didn't look like it would be an issue, but the OS was horribly unstable. The Crucial is a 9.5mm profile.
 

bkd0255

macrumors member
Dec 22, 2012
67
2
Arizona
Fusion success on MacBook Pro 8,3

Had no problem creating a fusion drive on my 2011 MacBook Pro 17. Have a toshiba it originally came with 750 gigs and a Samsung 840 256.
 

petterihiisila

macrumors 6502
Nov 7, 2010
404
304
Finland
I got kernel panics after upgrading to 10.8.3 latest betas on my Mac Pro. I know it's beta, but it was so systematic that decided to dig a bit.

The panic log says "Where's my encryption context?\n" and I haven't found anything from Google with that.

Panic can be reproduced in 2 situations: 1) After an update to .3 beta, booting from the non-Fusion main drive (early in the boot); 2) or booting from the Fusion drive in 10.8.3 or 10.8.2 (late in the boot, after login).

After trying things out, it looks like my CoreStorage encrypted Fusion drive Data partition plays some role in it. It's not the primary drive. I use it to run VMWare (Data partition, encrypted) and to make a nightly bootable SuperDuper copy of my main drive (not encrypted). That way I have a 2nd bootable drive if things go bad with the main boot drive, and I can also try dubious hacks on that 2nd boot drive before taking them into actual use.

Panics were annoying, because I wanted to try 10.8.3 in advance, and I wanted to boot from my nightly mirror without a worry. Fusion is nice, because it makes booting from the mirror faster.

Since the panic log mentioned a problem with encryption, I removed CoreStorage encryption from the Fusion drive Data partition, and haven't had kernel panics after that for a few days days. I was able to update the main SSD pair to 10.8.3 beta and the system can now be booted from the non-encrypted Fusion drive boot partition too. All OK with that.

This might be a peculiar bug or feature due to the rest of my setup - the system has lots of hardware, drives and drivers running - but in case you get kernel panics with home-made Fusion drive, try disabling CoreStorage encryption from the Fusion partitions. Decrypt can be started from from Finder or via command line.

The peculiar thing is that I was not able to get 10.8.3 booting from my MAIN drive until I removed CS encryption from the SECONDARY drive. The main drive is neither Fusion nor encrypted. It's a pair of SSDs running in Apple SW RAID1 for capacity and speed.

Not blaming Apple, this isn't a supported setup. Just sharing the observation in case others have trouble with this.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.