Apple's New 'Fusion Drive' Not a Typical Hybrid Drive

[AidenShaw]

An honest question - can anyone with one of these systems describe what it looks like to the user?

Is the dual-partition nature of the fused drive visible, or is there a logical volume manager layer so that the user only sees the 1.128 TB volume?

Windows NT has had a logical volume manager since forever that shows the users a logical view of storage that's quite different from the actual physical view.

For example, on my home PC I have a 12 TB volume for virtual machine images. I have a second 12 TB volume where I mirror the virtual machine images.

When I look at the filesystems from the user view, I see two 12 TB disks. (attached image) There's nothing visible at the user level to distinguish these disks from a real 12 TB drive.

When I look at the disks from the administrator level DISKMGMT utility, however, I see that each 12 TB volume is really a RAID-0 stripe set of four 3TB disks. (attached thumbnail - but I only show 4 of the 8 drives)

Does the Apple OSX user see a single 1.128 TB volume unless they open root-level tools?

[perldude69]

I think it would be awesome if Apple put a 1 TB OCZ Colossus LT 3.5” Solid State Drive in their iMacs. I have about 400 GB of data on my 2009 iMac, and 1 TB would suffice for all of my data storage needs. Anything above and beyond would go on external storage.

[tardypooper]

i don't know about you guys, but since this is more of a software thing that something that takes place inside the machine itself, I was wishing it was possible to modify the software to present both drives as 2 separate volumes instead.

While this is good technology in action, somehow i just don't like having the control over which things I want taking priority over the others in my SSD. Btw, does anyone know if the 21.5" iMac is user-upgradable in terms of it's Hard Drive? I heard you can't upgrade it's RAM because it's soldered to the mother board.

[Macman45]

Originally Posted by gregwyattjr

This feature is perfect during this HD to SDD transitional period. It'll keep things affordable while still supplying great performance.

I think that's the most accurate and sensible comment I've read here all year.! It will indeed allow for complete transition when larger and more reliable SSD's are available, tested and pass Apple's R and D procedures where are tough.

A buddy is going to buy an imac with the 1TB Fusion drive as soon as they go on sale...(Probably next Monday, but don't quote me on this) So will get a chance to see how well they perform, and how reliable they prove to be. My own major upgrade date is early spring next year, and the FD will have a big bearing on what I buy then. A 27" maxed out imac as I have now, or a Pro...Personally I think the Pro may well be dead, but this isn't the right place to discuss that one.

[djrod]

Originally Posted by tardypooper

i don't know about you guys, but since this is more of a software thing that something that takes place inside the machine itself, I was wishing it was possible to modify the software to present both drives as 2 separate volumes instead.

While this is good technology in action, somehow i just don't like having the control over which things I want taking priority over the others in my SSD. Btw, does anyone know if the 21.5" iMac is user-upgradable in terms of it's Hard Drive? I heard you can't upgrade it's RAM because it's soldered to the mother board.

Nonsense, it's not soldered, it's just not easily accessible like it is now, you need to open the iMac to change the RAM just as you need to change the HD

[tardypooper]

Originally Posted by djrod

Nonsense, it's not soldered, it's just not easily accessible like it is now, you need to open the iMac to change the RAM just as you need to change the HD

Really? I thought I saw on BGR that states that "
The 21.5-inch iMac now joins the MacBook Air and 13 and 15-inch MacBook Pro with Retina display as computers with soldered RAM. "

Link: http://bgr.com/2012/10/24/apple-imac-non-upgradable-ram/

[djrod]

Originally Posted by tardypooper

Really? I thought I saw on BGR that states that "
The 21.5-inch iMac now joins the MacBook Air and 13 and 15-inch MacBook Pro with Retina display as computers with soldered RAM. "

Link: http://bgr.com/2012/10/24/apple-imac...pgradable-ram/

I was pretty sure I read it somewhere, but I can't find it, so maybe it was just wishful thinking

We'll have to wait for the iFixit tear down I guess

[Mal]

Originally Posted by tardypooper

Really? I thought I saw on BGR that states that "
The 21.5-inch iMac now joins the MacBook Air and 13 and 15-inch MacBook Pro with Retina display as computers with soldered RAM. "

Link: http://bgr.com/2012/10/24/apple-imac...pgradable-ram/

BGR isn't an official source. From the designs they showed in the keynote and the specs described by Apple, it looks likely that the 21.5" iMacs do not have soldered RAM, but that it is simply not accessible via a memory door like previous models. That means it's not user-replaceable, but it may be replaceable/upgradeable by Apple Stores or Service Centers.

jW

[tardypooper]

Boy am I relieved to hear that, I'm still pretty much contemplating between the 21.5" and 27" models though, heard OWC has released an update that Apple is further restricting the ability to upgrade hard drives and that's quite holding me back.
Link: http://blog.macsales.com/10146-apple-further-restricts-upgrade-options-on-new-imacs

Thanks for the heads up though

[hfg]

Originally Posted by tardypooper

Boy am I relieved to hear that, I'm still pretty much contemplating between the 21.5" and 27" models though, heard OWC has released an update that Apple is further restricting the ability to upgrade hard drives and that's quite holding me back.
Link: http://blog.macsales.com/10146-apple...s-on-new-imacs

Thanks for the heads up though

That OWC article is from May 2011 ... and it is regarding the temp sensor of the disk drives which has been discussed in many threads here.

[hfg]

Originally Posted by tardypooper

i don't know about you guys, but since this is more of a software thing that something that takes place inside the machine itself, I was wishing it was possible to modify the software to present both drives as 2 separate volumes instead.

While this is good technology in action, somehow i just don't like having the control over which things I want taking priority over the others in my SSD. Btw, does anyone know if the 21.5" iMac is user-upgradable in terms of it's Hard Drive? I heard you can't upgrade it's RAM because it's soldered to the mother board.

If you look at the Unix "diskutil" commands built into the current version of OS X, you will see the commands which are used to create the CoreStorage volume and then join them into what is called "Fusion" by Apple. It appears that there are also the necessary commands to delete and revert the CoreStorage drives back to its native type.

So, if you order a system with a Fusion drive, it appears that you can "undo" the Fusion functionality and restore the system to separate drives as desired.


-howard

[tardypooper]

Originally Posted by hfg

If you look at the Unix "diskutil" commands built into the current version of OS X, you will see the commands which are used to create the CoreStorage volume and then join them into what is called "Fusion" by Apple. It appears that there are also the necessary commands to delete and revert the CoreStorage drives back to its native type.

So, if you order a system with a Fusion drive, it appears that you can "undo" the Fusion functionality and restore the system to separate drives as desired.


-howard

oh thanks for the heads up Howard, it totally did clarify a lot for me, big thanks!

[haravikk]

Okay, so this feature has been out for a while now, but I've got a couple of questions since I still haven't yet made the switch:

Fusion Drive and RAID
Has anyone tried combining an AppleRAID of HDDs with an SSD into a Fusion Drive? My current setup is 4 HDD's in a RAID-0 for most files, and an SSD for OS and apps, but a Fusion Drive would be so much easier, but only if it will work as expected.

I'm assuming it should, as I think my SSD reads at about the same speed as a sustained read on a large file on the RAID-0 array, but should hopefully accelerate small file reads a lot better overall.

Fusion Drive and Metadata
Does anyone know where file-system metadata is stored on a Fusion Drive? Is it split between the two drives, or does the SSD accelerate file-system management as well? I'm hoping for the latter, as if CoreStorage kicks in at the block level (below the file system) then file-system data and the files themselves should be indistinguishable.

I don't suppose anyone knows for sure, or can devise a test to find out?

[ipmasta]

Originally Posted by cgk.emu

Until the hard drive in your time capsule fails....

The time capsule acts as a backup - therefore if your time capsule hard drive fails you still have your data on your computers hard drive - unless your just had the unlikely scenario that both your time capsule hard drive and your computers hard drive go out at the same time. Im just glad my time capsule is still under warranty.