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Apple's New Fusion Drive Works on Older Macs

Dang, wish I had thought to leave my recovery partition. I did the "100%" thing and while I remembered to save my Win 7 partition I forgot about the recovery partition. If anyone has success re-adding the recovery partition let me know! Thanks.
 
ArsTechnica posted their own hands-on creating a Fusion Drive, and has considerably more details. Long and short ...

Commenters in the other articles—particularly those who only skimmed the texts—have wondered at length why we're spending so much (virtual) ink covering Fusion Drive. Isn't it just a plain caching solution? Isn't it the same as Intel SRT? Hasn't Linux been doing this since 1937?

No, no, and no.
Click to expand...

Picture Fusion Drive's SSD like a small drinking glass, and the HDD is a much larger bucket, below the SSD. When you put data onto a Fusion Drive, it's like you're pouring water into the glass; eventually, as the glass fills, water slops over the side and begins to be caught by the bucket. With Fusion Drive, you always pour into the glass and it spills into the bucket as needed.
Click to expand...
(This is an imprecise analogy, as it doesn't indicate how to get water from the bucket into the glass for faster access, but it'll do.)

In caching, the HDD is the storage device with which you interact, and the SSD is used to augment the speed of the HDD. In Fusion Drive, the SSD is the device with which you interact and the HDD is used to augment the capacity of the SSD.
Click to expand...
(Emphasis is mine.)

http://arstechnica.com/apple/2012/1...ining-doc-ars-tears-open-apples-fusion-drive/

I'm going to wipe my 2011 Mac Mini and set up a Fusion Drive as soon as I can get a great deal on a 128GB SSD. I'm sure I can do better than the $90 for a Samsung 830.
 
Just for the hack of it, I tried what happens if I scrap my RAID-0 SSD pair and let CoreStorage do the striping. Turns out that it is not any better idea than it sounds.

I do get full-disk encryption, restore partition and other benefits that the software-RAID-as-boot-disk lacked, but the speeds indeed go down to single-SSD level. I get a lot of beach balls too. It just isn't snappy. In fact it feels slower than a single SSD.

To me it's confirmed that there is no hidden RAID-0-like behavior in CoreStorage, not at least yet. Also any Fusion Drive -like behavior doesn't happen. If I read from one disk, nothing happens on the second. The data is distributed, but it's not evenly distributed. One disk gets stressed more than the other in regular use. It's essentially JBOD.

Maybe that was only to be expected, but I tried it so you don't have to! 😀

(I think it was worth a try, since Fusion Drive behavior wasn't advertised either, yet it was there. Apple will probably add RAID-like features into CoreStorage down the road, but that day isn't today.)

--> I'll revert back to RAID-0 and put an encrypted CoreStorage on top of that to get even distribution of data between disks. And wipe the SSDs while I'm at it. It's been a while since I reset them to factory state.
 
petterihiisila said:
Just for the hack of it, I tried what happens if I scrap my RAID-0 SSD pair and let CoreStorage do the striping. Turns out that it is not any better idea than it sounds.

I do get full-disk encryption, restore partition and other benefits that the software-RAID-as-boot-disk lacked, but the speeds indeed go down to single-SSD level. I get a lot of beach balls too. It just isn't snappy. In fact it feels slower than a single SSD.

To me it's confirmed that there is no hidden RAID-0-like behavior in CoreStorage, not at least yet. Also any Fusion Drive -like behavior doesn't happen. If I read from one disk, nothing happens on the second. The data is distributed, but it's not evenly distributed. One disk gets stressed more than the other in regular use. It's essentially JBOD.

Maybe that was only to be expected, but I tried it so you don't have to! 😀

(I think it was worth a try, since Fusion Drive behavior wasn't advertised either, yet it was there. Apple will probably add RAID-like features into CoreStorage down the road, but that day isn't today.)

--> I'll revert back to RAID-0 and put an encrypted CoreStorage on top of that to get even distribution of data between disks. And wipe the SSDs while I'm at it. It's been a while since I reset them to factory state.
Click to expand...

Based on how the Fusion Drive is intended to work (using a slower hard drive to add capacity to a faster SSD), putting two SSDs together in this manner would have no benefit other than using the faster drive first, and giving you a single pooled storage volume.
 
SuperRob said:
Based on how the Fusion Drive is intended to work (using a slower hard drive to add capacity to a faster SSD), putting two SSDs together in this manner would have no benefit other than using the faster drive first, and giving you a single pooled storage volume.
Click to expand...

Of course. My intent was to test if there was RAID-0-like functionality hidden in CoreStorage, if it sees two SSD's. After all, Fusion Drive behavior itself was hidden until someone tried it.

Turns out, as expected at this point, it became just a pooled storage volume. For reasons that are not so obvious, the result felt a lot slower than a single SSD. I didn't run benchmarks, but I hadn't really seen beach balls for SSD I/O wait before this trial. At times the boot disk and the whole system was stuck at something. That's why I'll revert to good old RAID-0 and a healthy array of backups.

Blogs linked in this thread have also speculated, if Apple might in the future use CoreStorage to replace software RAID. But who knows when, if at all.

BTW, are you sure it uses "the faster drive first?" How would it know, other than "this is an SSD and that is not?" I doubt CoreStorage runs benchmarks to choose what must be the faster drive. (In my case they were identical drives, Vertex 2.)
 
petterihiisila said:
Of course. My intent was to test if there was RAID-0-like functionality hidden in CoreStorage, if it sees two SSD's. After all, Fusion Drive behavior itself was hidden until someone tried it.

Turns out, as expected at this point, it became just a pooled storage volume. For reasons that are not so obvious, the result felt a lot slower than a single SSD. I didn't run benchmarks, but I hadn't really seen beach balls for SSD I/O wait before this trial. At times the boot disk and the whole system was stuck at something. That's why I'll revert to good old RAID-0 and a healthy array of backups.

Blogs linked in this thread have also speculated, if Apple might in the future use CoreStorage to replace software RAID. But who knows when, if at all.

BTW, are you sure it uses "the faster drive first?" How would it know, other than "this is an SSD and that is not?" I doubt CoreStorage runs benchmarks to choose what must be the faster drive. (In my case they were identical drives, Vertex 2.)
Click to expand...

In one of the reports linked in these forums, it was suggested that the drive "Smart Status" was interrogated to identify the drive as a SSD, and thus the faster drive. In your case, with both drives SSD, the status would not identify the faster drive (equal), so maybe it just builds them in the order the drive-ID is specified, or by relative size?

Thanks for your information on CoreStorage RAID-0 tests. 🙂

I wonder if software RAID-0 arrays could be joined as a "Fusion" drive?



-howard
 
Just checking back in to say that after using my "Fusion" drive for a few days, it is a little slower at some tasks than just using the SSD as the main drive like I used to do. Occassionally I get beachballs when something from the HDD needs to be accessed. I notice it a lot in Xcode. The trade off is that I don't have to do any admin work keeping my files in order between the SSD and the HDD. I haven't decided yet if the trade off is worth it... right now I feel like it is but if you already use an SSD as your main drive and a HDD for your data you may disagree.
 
rockstarjoe said:
Just checking back in to say that after using my "Fusion" drive for a few days, it is a little slower at some tasks than just using the SSD as the main drive like I used to do. Occassionally I get beachballs when something from the HDD needs to be accessed. I notice it a lot in Xcode. The trade off is that I don't have to do any admin work keeping my files in order between the SSD and the HDD. I haven't decided yet if the trade off is worth it... right now I feel like it is but if you already use an SSD as your main drive and a HDD for your data you may disagree.
Click to expand...

If the content you accessed was coming from the hard drive, you'll see that. As if the content is accessed a few more times, though, it should get promoted to the SSD, so the problem should effectively resolve itself.
 
hfg said:
As I mentioned previously, I did not destroy all the partitions on my drives prior to setting them up as a "Fusion" drive. I wanted to maintain my Windows Boot partition on the SSD if possible, so I joined the "partition-ID" on the SSD and the "disk-id" on the hard disk and it worked. 🙂

It appears that the Apple Boot Recovery HD partition was also saved by doing this.
I used the "100%" entry for the fusion disk size.

Here is my disk list:

Code: 
[COLOR="Blue"]diskutil list
/dev/disk0
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *240.1 GB   disk0
  1:                        EFI                         209.7 MB   disk0s1
  2:          Apple_CoreStorage                         158.8 GB   disk0s2
  3:                 Apple_Boot Recovery HD             785.0 MB   disk0s3
  4:       Microsoft Basic Data Windows SSD             80.2 GB    disk0s4

/dev/disk1
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:      GUID_partition_scheme                        *500.1 GB   disk1
  1:                        EFI                         209.7 MB   disk1s1
  2:          Apple_CoreStorage                         499.8 GB   disk1s2
  3:                 Apple_Boot Boot OS X               134.2 MB   disk1s3

/dev/disk2
  #:                       TYPE NAME                    SIZE       IDENTIFIER
  0:                  Apple_HFS Macintosh Fusion       *655.5 GB   disk2
[/COLOR]

I also did a Time Machine backup prior to the disk join, and used it to restore the "Fusion" drive with no problems.


-howard
Click to expand...

so you used disk0s2 and disk1 while creating the logical volume group, formatted to jhfs+ and proceeded like everyone else did right?

also how is this working out for you? if all is well i might just keep the recovery partition and my efi and just "fuse" the existing mac volume + new ssd. Hope that doesn't create a second recovery partition though.
 
emir said:
so you used disk0s2 and disk1 while creating the logical volume group, formatted to jhfs+ and proceeded like everyone else did right?

also how is this working out for you? if all is well i might just keep the recovery partition and my efi and just "fuse" the existing mac volume + new ssd. Hope that doesn't create a second recovery partition though.
Click to expand...

That is correct ... I used the existing SSD "partition-ID" along with the hard disk "disk-ID" when creating the "Fusion" drive using the same method as everyone else. I then did a clean install of Mountain Lion to the newly created "Fusion" drive and migration feature presented during OS X setup to pull my data from Time Machine backup performed immediately prior to starting the conversion.

It seems to be working fine so far. I have added a considerable amount of data (photo and music libraries) which previously was managed manually on the hard drive without any issues. Everything seems fast and I like the single logical drive solution with the classic OS X file tree.

I can boot back and forth into Windows and OS X as expected, with the Windows image on the SSD for speed.


-howard
 
I plan to do this with my current 7200rpm 500 gb HDD and a 120 or 128 gb SSD. My question is regarding what "kit" to get. I can get the OptiBay kit and Samsung 830 series 128 gb SATA III drive for about $145. Or the OWC data doubler and OWC 120 gb SATA II drive for $155. Which would people recommend?

I have a 2010 MBP so I don't need SATA III, though the Samsung is future-proof. I know OWC offers a SATA 3 drive, but it's $188 and for that price I'd definitely get the OptiBay/Samsung combo. I'm intrigued by the inexpensive adapter options, like the one from Amazon for $11, but I'm leery of the price difference. Especially since if it's connection fails the whole system could be compromised (since it's a Fusion setup).

EDIT: decided to just get this eBay caddy and this eBay SuperDrive enclosure plus the Samsung drive. Total $131, so cheaper than the other two options and includes the SuperDrive enclosure. After reading some other threads on MacRumors it seems like the eBay ones do just fine. I barely use my SuperDrive (think the last time I used it was to install Office 2011) and I'm putting the SSD in the caddy so I'm not worried about vibration. I'll update after I get my Fusion drive set up.

One thing I have read is that removing the SuperDrive voids your warranty, so for any warranty work I'd need to put the SuperDrive back in. But with a Fusion setup this wouldn't be possible without a lot of headache. Just something to think about...
 
Last edited:
Is there a ODD caddy that accepts straight MBA style "blade" SSD?
Does MBA sized SSD also fit in rMBP?
(I'm thinking if I could buy a SSD that can be cycled through all kind of macs I could own in the future... First years in MP, next in MBP and rest of its life in MBA...)
 
Just bought a 128GB Crucial M4 from NewEgg for $79 shipped. Planning on getting my Fusion Drive going over the Thanksgiving break. 🙂
 
SuperRob said:
Just bought a 128GB Crucial M4 from NewEgg for $79 shipped. Planning on getting my Fusion Drive going over the Thanksgiving break. 🙂
Click to expand...

Wow ... that was quick ... they are out of stock already.

I just got the email from Newegg this morning with the 24 hr. deal on those SSD drives for $78.74 with the promo code.

----------
toke lahti said:
Is there a ODD caddy that accepts straight MBA style "blade" SSD?
Does MBA sized SSD also fit in rMBP?
(I'm thinking if I could buy a SSD that can be cycled through all kind of macs I could own in the future... First years in MP, next in MBP and rest of its life in MBA...)
Click to expand...

If you look at the OWC replacement "blade" SSD drives, they appear to be different for the MBA and rMBP. I haven't seen a ODD caddy for those, but it is a good idea ... perhaps OWC will make one as they do make external enclosures for the drive you remove when upgrading so that you can still get some use out of it.

Hopefully the new iMacs will accept one or the other of the existing drives. That would also give up-graders of these machines a market for their old SSD blades for the new base level iMacs owners looking to add a SSD for Fusion. 🙂
 
ordered my caddy and superdrive enclosure from the internet. it has shipped. in the mean time i will update my bootable usb to 10.8.2 from 10.8. Time machine backup my mac and buy an sad.

since i have 2010 macbook 15" it only supports sata 2, not 3. so i am thinking of buying intel 330 ssd 120 GB what do you think?
 
emir said:
ordered my caddy and superdrive enclosure from the internet. it has shipped. in the mean time i will update my bootable usb to 10.8.2 from 10.8. Time machine backup my mac and buy an sad.

since i have 2010 macbook 15" it only supports sata 2, not 3. so i am thinking of buying intel 330 ssd 120 GB what do you think?
Click to expand...
I'm in the same boat as far as only having SATA 2. Not sure on the price of the Intel, but I opted to get the Samsung 830 series 128 GB for $90 from Newegg. It's SATA 3, so I figure if I upgrade my computer to a new MBP in the future (as opposed to MBA or rMBP) it's future-proof. Also could be used in a SATA 3 Thunderbolt or USB 3 enclosure in the future.

----------
emir said:
ordered my caddy and superdrive enclosure from the internet. it has shipped. in the mean time i will update my bootable usb to 10.8.2 from 10.8. Time machine backup my mac and buy an sad.

since i have 2010 macbook 15" it only supports sata 2, not 3. so i am thinking of buying intel 330 ssd 120 GB what do you think?
Click to expand...
Is your bootable USB a full-blown OS X install, or are you talking about a bootable OS X installation drive? Assuming you're talking about an installation drive, is there an easy way to upgrade it to 10.8.2, or do you have to download the entire 10.8.2 from the App Store and redo the bootable drive?
 
I have been unable to duplicate these results.
I have a MacbookPro8,2 and an iMac 11,1. Both with a 240GB SSD and a 1TB HDD.

Both have the same data on them, about 400G total. I have yet to see anything showing that the data is being moved.
 
hfg said:
If you look at the OWC replacement "blade" SSD drives, they appear to be different for the MBA and rMBP.
Click to expand...
But if they have same kind of attachment (hole for screw?) and MBA's is only smaller by its width, then it should fit also to rMBP.
 
Transeau said:
I have been unable to duplicate these results.
I have a MacbookPro8,2 and an iMac 11,1. Both with a 240GB SSD and a 1TB HDD.

Both have the same data on them, about 400G total. I have yet to see anything showing that the data is being moved.
Click to expand...

With >50% of your data on the SSD, it may be that you're not accessing any data that is stored on the HDD. Have you been using Terminal to track data movement?
 
football751 said:
Is your bootable USB a full-blown OS X install, or are you talking about a bootable OS X installation drive? Assuming you're talking about an installation drive, is there an easy way to upgrade it to 10.8.2, or do you have to download the entire 10.8.2 from the App Store and redo the bootable drive?
Click to expand...

i redownloaded 10.8.2 from the app store and will format my usb and make a bootable usb again. and by bootable mean an installation drive.
 
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