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.
I can confirm that recovery partition DOES exist. I was able to go into recovery mode by pressing CMD+R while booting.
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.
(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.)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.
(Emphasis is mine.)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.
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.
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.
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.)
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.
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
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.
I would like to add regarding TRIM on SSD
Since my SSD is not from Apple, so TRIM by default is not supported. After Fusion Drive, I was worried about trying the TRIM patch by: http://www.groths.org/?page_id=322
I applied it last night and worked without any issues.
Just bought a 128GB Crucial M4 from NewEgg for $79 shipped. Planning on getting my Fusion Drive going over the Thanksgiving break.
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...)
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.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?
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?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?
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.If you look at the OWC replacement "blade" SSD drives, they appear to be different for the MBA and rMBP.
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.
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?