Disable Fusion Drive

[themcfly]

1. Why not if you use those file blocks the most?
2. You want to save a few seconds on loading a program that you only use a couple times a year? ok
3. I kind of doubt you're "stressing" the HDD. It was designed to, you know, read and write things millions of times.
4. I don't question that different users have different needs. I do question when those needs don't make sense.

Don't let the Apple "man" keep you down!

1/2/3. I don't know why i should wait for an application to load its thousand of small files scattered on the drive when it can be istantly ready loading from an SSD, while working on a video file, that is basically sequential reading, makes no difference at all. Also, hard disks are designed to read and write things millions of times, but they just tend to fail on the long run compared to SSDs. Maybe my drive will fail anyway, but since swapping it in an iMac is a bit of a trouble, I don't know why I should overload it when I exactly know what I need and when I need it: sometimes I just turn on my iMac in the weekend to browse the internet and listen to some music, and the hard drive doesn't even spin up. Just picturing Fusion scattering my files on the two drives the way he wants it's so bad to me it hurts. And what if that fail actually happens? While un-fused, you simply turn on your iMac, attach your Time Machine, and boom, you're ready to work with your applications on the SSD drive like you left them the day before. On Fusion? Congratulations, you just lost your job.
4. I think these reasons are making a lot of sense, at least to me. It's not only about real-world speeds, but a mix of all the factors listed above. I just know how to manage my files and applications, so just leave them the way I want them to be.

I love my new iMac, but as a professional Fusion Drive just bothers me, and that's why I un-fused and I'm happy with it. Other users, maybe upgrading from simple HDD, will find it unbelievably fast. Just let anyone pick his poison.

 

[Nuke61]

I love my new iMac, but as a professional Fusion Drive just bothers me, and that's why I un-fused and I'm happy with it. Other users, maybe upgrading from simple HDD, will find it unbelievably fast. Just let anyone pick his poison.

I just don't see the sense in spending a $250 premium for what has become, in effect, paying $250 for a 128GB SSD. You have also effectively doubled your backup requirements.

 

[Arfdog]

1/2/3. I don't know why i should wait for an application to load its thousand of small files scattered on the drive when it can be istantly ready loading from an SSD, while working on a video file, that is basically sequential reading, makes no difference at all. Also, hard disks are designed to read and write things millions of times, but they just tend to fail on the long run compared to SSDs. Maybe my drive will fail anyway, but since swapping it in an iMac is a bit of a trouble, I don't know why I should overload it when I exactly know what I need and when I need it: sometimes I just turn on my iMac in the weekend to browse the internet and listen to some music, and the hard drive doesn't even spin up. Just picturing Fusion scattering my files on the two drives the way he wants it's so bad to me it hurts. And what if that fail actually happens? While un-fused, you simply turn on your iMac, attach your Time Machine, and boom, you're ready to work with your applications on the SSD drive like you left them the day before. On Fusion? Congratulations, you just lost your job.
4. I think these reasons are making a lot of sense, at least to me. It's not only about real-world speeds, but a mix of all the factors listed above. I just know how to manage my files and applications, so just leave them the way I want them to be.

I love my new iMac, but as a professional Fusion Drive just bothers me, and that's why I un-fused and I'm happy with it. Other users, maybe upgrading from simple HDD, will find it unbelievably fast. Just let anyone pick his poison.

Ok, joking aside, you're speaking from a total lack of experience with the fusion drive. I have mine filled with about 270 gb and there is absolutely no difference in performance from an SSD. Time Machine will restore data to a fusion drive Mac perfectly fine. What are you talking about?

That's fine that you have your way, but I want to clear the air for other normal users here because you're explicitly making wrong statements.

 

[themcfly]

I just don't see the sense in spending a $250 premium for what has become, in effect, paying $250 for a 128GB SSD. You have also effectively doubled your backup requirements.

Do i have any alternative? I liked better the combination 256GB SSD + 1TB HDD of 2011 and previous iMacs, but eventually Apple decides to leave behind the pro segment (google Mac Pro) because is clearly not profitable enough. But 150-200€ for a software trick, yes, that is profitable.

Ok, joking aside, you're speaking from a total lack of experience with the fusion drive. I have mine filled with about 270 gb and there is absolutely no difference in performance from an SSD. Time Machine will restore data to a fusion drive Mac perfectly fine. What are you talking about?

That's fine that you have your way, but I want to clear the air for other normal users here because you're explicitly making wrong statements.

I think you'll have to read my answer again instead. As i said, it's not only about speed, but also the other factors combined. Also, I'm sure you are amazed every time you open up iTunes in a tenth of a second on your new Fusion Drive: now try loading After Effects with hundreds of plugins installed, let alone all the standard tiny system and bundles files he has to load on every startup (about 800+ files), and compare the differences doing that from an HDD and an SSD. Then you'll know what we're talking about here.

And no, when your HDD fails with Fusion, you just take you iMac and bring it to the Apple Store, and wait 3-4 days to the replacement to be made. Maybe you even bought it online and you're off the first year warranty, so you'll even have to take it and ship it by post.

With separated drives, you just boot in to the SSD and work you files off of Time Machine. Istantly. "Wrong statements" much?

 

[Nuke61]

Do i have any alternative?

Absolutely... if you just must have a separate SSD, use Thunderbolt or USB 3.0 and use an external SSD with the base 1TB hard drive. For 50% more than the price of the Fusion option you can get an external SSD that has twice the storage space. It was an option that I considered, but I didn't want the backup hassle of having two drives. Instead, I backup the Fusion drive to the SSDs.

With separated drives, you just boot in to the SSD and work you files off of Time Machine. Istantly. "Wrong statements" much?

With my Fusion drive, I just boot off one of my external SuperDuper! clone drives. It doesn't matter if the SSD or the HDD portion fails, my response is exactly the same. What happens if your boot SSD fails? Where's the backup for that?

I'm big on backups, and the biggest issue I see with split drives is a doubling of backups. As it is I have a backup to three external SSDs, TimeMachine backups to a NAS, DiskImage on the NAS, NAS backup to a 2nd NAS, and CrashPlan for offsite. Backup obsessed, I know, but once bitten...

 

[themcfly]

Absolutely... if you just must have a separate SSD, use Thunderbolt or USB 3.0 and use an external SSD with the base 1TB hard drive. For 50% more than the price of the Fusion option you can get an external SSD that has twice the storage space. It was an option that I considered, but I didn't want the backup hassle of having two drives. Instead, I backup the Fusion drive to the SSDs.

Don't personally like the external solution, considering equal SSD size the price is almost the same than internal. What's wrong with unfusing?

With my Fusion drive, I just boot off one of my external SuperDuper! clone drives. It doesn't matter if the SSD or the HDD portion fails, my response is exactly the same. What happens if your boot SSD fails? Where's the backup for that?

The backup is obviously on Time Machine. I'm willing to risk that remotely low probability that my SSD fails, instead of having the hassle of drive cloning and the known side effects of Fusion.

I had 2 iMacs before this, and both suffered HDD failure. That's also why i'm so against Fusion.

 

[flynz4]

Ok, joking aside, you're speaking from a total lack of experience with the fusion drive. I have mine filled with about 270 gb and there is absolutely no difference in performance from an SSD. Time Machine will restore data to a fusion drive Mac perfectly fine. What are you talking about?

That's fine that you have your way, but I want to clear the air for other normal users here because you're explicitly making wrong statements.

Regarding the bolded section above... There certainly is a difference between a pure SSD and a FD. Your post over-states the advantages of FD.

Having said that... FD is pretty damn good. For most users... it is a "good enough approximation" of a full SSD experience. Other than to someone who simply cannot afford the $250 cost adder... I cannot imagine why I would not recommend a FD wholeheartedly. It is a bargain. I cannot imagine personally buying an iMac for anyone in my family without the minimum of FD.

For those who need more than FD... I think that the 768GB option was a "fair" upgrade. It is still not good enough... but it is not bad. In the next few years, we will see SSD capacity continue strong capacity growth and improved affordability... coupled with a dramatic increase in performance.

I will personally upgrade from my 2012 iMac in ~3 years... and I expect that the SSD options will be at 2TB or higher by then. I might upgrade sooner if we get to 2TB earlier.

/Jim

 

[Nuke61]

Don't personally like the external solution, considering equal SSD size the price is almost the same than internal. What's wrong with unfusing?

If un-fusing is what you prefer, there's nothing wrong with it in your situation, but there were and are still alternatives using an external SSD.

The backup is obviously on Time Machine. I'm willing to risk that remotely low probability that my SSD fails, instead of having the hassle of drive cloning and the known side effects of Fusion.

The hassle of drive cloning? I installed SuperDuper! and hooked up all 3 external SSDs. In SD I set up a schedule to clone to SSD1 every day, SSD2 every other day, and SSD3 once a week. There is nothing else to do, it's handled automatically by the SD scheduler. A hassle? To the contrary, it can't get much simpler and hassle free.

If the Fusion drive fails, I reboot and hold down the Option key, select an external drive, and I'm back up and running. This happens, quite literally, in a few handful of seconds. No restoration required, since I've booted off of a fully functional clone on my boot and data drive.

How is the TimeMachine backup done? Do you have two TM drives? I know you can tell TM to backup your boot drive and ignore your HDD data drive, but can you have two different TM backups going to the same TM drive?

 

[themcfly]

How is the TimeMachine backup done? Do you have two TM drives? I know you can tell TM to backup your boot drive and ignore your HDD data drive, but can you have two different TM backups going to the same TM drive?

I just tell Time Machine to backup all my system, it does that to a single drive for both of the physical drives of the iMac.

 

[Arfdog]

Regarding the bolded section above... There certainly is a difference between a pure SSD and a FD. Your post over-states the advantages of FD.

Having said that... FD is pretty damn good. For most users... it is a "good enough approximation" of a full SSD experience. Other than to someone who simply cannot afford the $250 cost adder... I cannot imagine why I would not recommend a FD wholeheartedly. It is a bargain. I cannot imagine personally buying an iMac for anyone in my family without the minimum of FD.

For those who need more than FD... I think that the 768GB option was a "fair" upgrade. It is still not good enough... but it is not bad. In the next few years, we will see SSD capacity continue strong capacity growth and improved affordability... coupled with a dramatic increase in performance.

I will personally upgrade from my 2012 iMac in ~3 years... and I expect that the SSD options will be at 2TB or higher by then. I might upgrade sooner if we get to 2TB earlier.

/Jim

FD isn't for everyone, but it is a great compromise for most people. I can nary notice any slowdown at all, and i'm not exaggerating. I also base my opinion off normal usage, I don't manage enormous 15 gb files, as I imagine most people don't as well.

 

[Nuke61]

I just tell Time Machine to backup all my system, it does that to a single drive for both of the physical drives of the iMac.

Thanks, I had no idea it would allow you to back up two physical drives and allow you to pick which drive you're restoring since I've always used single boot/data drive setups. Since I have multiple clones I've never needed to go to my TM backups.

 

[flynz4]

Responding to your previous post, I think it's a huge assumption that the HDD "will" fail, rather than "if" it fails. Both HDD and SSD are rated at >1 million hours MTBF. Basically the same failure rate.

I do not recall saying it would fail... nor does it sound like something that I would say.

The only thing that I can possibly think of is that in the past, I might have suggested having a backup strategy that assumes that devices will fail.

/Jim

 

[Arfdog]

I do not recall saying it would fail... nor does it sound like something that I would say.

The only thing that I can possibly think of is that in the past, I might have suggested having a backup strategy that assumes that devices will fail.

/Jim

Sorry, I totally mistakely responded to you on the second question! I meant to respond to Mcfly!

Apologies!

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Don't personally like the external solution, considering equal SSD size the price is almost the same than internal. What's wrong with unfusing?



The backup is obviously on Time Machine. I'm willing to risk that remotely low probability that my SSD fails, instead of having the hassle of drive cloning and the known side effects of Fusion.

I had 2 iMacs before this, and both suffered HDD failure. That's also why i'm so against Fusion.

I think it's a huge assumption that the HDD "will" fail, rather than "if" it fails. Both HDD and SSD are rated at >1 million hours MTBF. Basically the same failure rate.

Secondly, even if it does fail, your Time Machine will fix it. Why would Time Machine discriminate between a FD setup and a separate HD setup? What if the SSD is the one that fails?

 

[conexion]

mac mini 2012 split fusion drive

Ok i just successfully split my fusion drive into the SSD and HDD alone.

View attachment 384950

3TB HDD benchmark

View attachment 384948

128GB SSD benchmark

View attachment 384949

Hi, torana355,
I wonder after separating Fusion if the OS y applications left in the SSD and HDD everything else? It´s what to want. . It possible? If so, how you did it.

 

[portishead]

diskutil rename disk0s2 Macintosh HD
diskutil rename disk1s2 Data HD

I'm able to split my drives, and install correctly, but I can't figure out how to rename them in the terminal. Those commands didn't work for me. I just installed under "Untitled" and I'll rename it after unless someone else has an idea. Thanks.

 

[gnasher729]

I think it's a huge assumption that the HDD "will" fail, rather than "if" it fails. Both HDD and SSD are rated at >1 million hours MTBF. Basically the same failure rate.

"Mean time between failure" is not the same as "time until failure". The MTBF of 114 years basically claims that most hard drives will work until they wear out, and not fail before that. But they will wear out a lot quicker than after 114 years. And to most people, "wear out" is the same as "failure": The drive stops working.

 

[Arfdog]

"Mean time between failure" is not the same as "time until failure". The MTBF of 114 years basically claims that most hard drives will work until they wear out, and not fail before that. But they will wear out a lot quicker than after 114 years. And to most people, "wear out" is the same as "failure": The drive stops working.

What's the difference between failure and wearing out?

My point was the MTBF between SSD and HDD is similar. This McFly person thinks a HDD failure is imminent during the useful life of a PC. I've never had a HDD fail since my family's 286 computer with its 40 MB hard drives.... that still work today.

 

[Nuke61]

"Mean time between failure" is not the same as "time until failure". The MTBF of 114 years basically claims that most hard drives will work until they wear out, and not fail before that. But they will wear out a lot quicker than after 114 years. And to most people, "wear out" is the same as "failure": The drive stops working.

Just as an FYI, and I know that it was many years ago, but I'm guessing that not a lot has changed with regard to MTBF and actual failure rates since this USENIX paper was submitted. It basically concluded that actual failure rates FAR exceed failure rates that MTBF numbers suggest.

In this paper, we present and analyze field-gathered disk replacement data from a number of large production systems, including high-performance computing sites and internet services sites. About 100,000 disks are covered by this data, some for an entire lifetime of five years. The data include drives with SCSI and FC, as well as SATA interfaces. The mean time to failure (MTTF) of those drives, as specified in their datasheets, ranges from 1,000,000 to 1,500,000 hours, suggesting a nominal annual failure rate of at most 0.88%.

We find that in the field, annual disk replacement rates typically exceed 1%, with 2-4% common and up to 13% observed on some systems. This suggests that field replacement is a fairly different process than one might predict based on datasheet MTTF.

We also find evidence, based on records of disk replacements in the field, that failure rate is not constant with age, and that, rather than a significant infant mortality effect, we see a significant early onset of wear-out degradation. That is, replacement rates in our data grew constantly with age, an effect often assumed not to set in until after a nominal lifetime of 5 years.
http://static.usenix.org/events/fast07/tech/schroeder.html

 

[cmanderson]

What's the difference between failure and wearing out?

My point was the MTBF between SSD and HDD is similar. This McFly person thinks a HDD is imminent during the useful life of a PC. I've never had a HDD fail since my family's 286 computer with its 40 MB hard drives.... that still work today.

Just curious, but do you leave any machine on 24/7?

 

[Arfdog]

Just as an FYI, and I know that it was many years ago, but I'm guessing that not a lot has changed with regard to MTBF and actual failure rates since this USENIX paper was submitted. It basically concluded that actual failure rates FAR exceed failure rates that MTBF numbers suggest.

Well, what MTBF numbers suggests depends on one's understanding of statistics. MTBF is merely the result of a test of a large population of drives in order to help gage production quality, especially infant mortality. It does not directly predict the number of hours before failure of a drive, but it can be an indicator.

therefore you can compare two machines' production quality by their MTBF ratings. HDD and SSD have such high MTBF that it probably indicates long life before failure.

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Just curious, but do you leave any machine on 24/7?

Not if I can help it. Doesn't change the fact that HDD and SSD have similar MTBFs.

 

[themcfly]

Arfdog, you were the one treating us like idiots because we unfused our drives, always arguing about how we should use our computer like your way of using it is the only one that counts.

As far as I'm concerned, I had 2 failures in 2 previous iMacs, the second one before it was recalled (Late 2009). Also, I gave you an infinite list of reason, but you eventually derailed the discussion on this minor MTFB thing.

Just cause I'm feeling adding something to that list: How about a fresh install of Mavericks the day it comes out (or any fresh install whatsoever)? Got to move thousands of GB of files two times? And what if I want to put BOOTCAMP on the SSD drive?

Also, to all of you arguing that unfusing we just paid 250$ for a 128GB SSD... we are probably "newbs who think they are leet and power usery", but you just paid 250$ for a software trick that is also available in every other mac with ML...

I'm able to split my drives, and install correctly, but I can't figure out how to rename them in the terminal. Those commands didn't work for me. I just installed under "Untitled" and I'll rename it after unless someone else has an idea. Thanks.

Sorry I didn't point it out. In terminal, to write a space in a string, you have to use "\ " instead of the normal space. I'll edit the post, glad it helped.

 

[Nuke61]

Also, to all of you arguing that unfusing we just paid 250$ for a 128GB SSD... we are probably "newbs who think they are leet and power usery", but you just paid 250$ for a software trick that is also available in every other mac with ML...

I don't follow your logic - if someone buys an iMac without a Fusion drive, how did they pay $250 for a software trick that is also available in every other ML Mac?

 

[gnasher729]

What's the difference between failure and wearing out?

My point was the MTBF between SSD and HDD is similar. This McFly person thinks a HDD failure is imminent during the useful life of a PC. I've never had a HDD fail since my family's 286 computer with its 40 MB hard drives.... that still work today.

Consider the tires on your car. They will last a certain number of miles and then they wear out. But they should _fail_ very very rarely. You'll replace four tires after anything between 20,000 and 50,000 miles because they are worn out, but MTBF is much higher (you expect to drive 100 or 200 thousand miles without a tire failing).

 

[themcfly]

Ok, Mavericks is out, and best of all, it's free.

I always like to do a clean install when I upgrade OS, I know it sounds stupid but I'm used to it.

Do you think, while formatting the hard drive, the online recovery will download and install directly Mavericks instead of ML? Is anyone attempting something like this?

 

[yking90]

Drive Unmounting Automatically

OK! So I managed to split my 1TB Fusion Drive following the posts here and successfully installed OSX on the Boot (SSD) partition, with a space "Data" partition (non SSD) to store my media.

Strangely enough... I leave the iMac on for more than 24 hours and it automatically "unmounts" my DATA partition.

Could anyone provide me with any insights?

Here's my diskutil list:

diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Boot                    120.5 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 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_HFS Data                    999.9 GB   disk1s2
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *8.0 GB     disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS OS X 10.9 Mavericks ... 7.7 GB     disk2s2