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Advantage of Fusion over SSD+HDD separately

MrXiro

MrXiro

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Nov 2, 2007
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I have the 2012 Mac Mini and installed a 256gb Crucial M4 and still have the stock 1tb drive attached inside as well.

I currently have my OS on the SSD and all my iTunes music on the 1TB. My iTunes movies are kept on an external HDD (I'm hitting 800gb in movies)

Been reading a lot about the DIY Fusion drives, wondering if it's actually worth my while to do it or if it's just a high risk task of crashing out the drives and losing all my data one day?

Anyone successfully created a Fusion and is perfectly happy about it?
 
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dasx

dasx

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Jun 18, 2012
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Barcelona
There are threads on how to create your own. Search for "DIY fusion" and you'll find it. ;)

As for if it's worth it or not… Not in my case. There's been some discussion on the topic and some will tell you it's amazing, I just don't like it. I do understand though it being so useful for the most part of users out there.
 
nuckinfutz

nuckinfutz

macrumors 603
Jul 3, 2002
5,539
406
Middle Earth
I think the concept of Fusion Drive is superior.

If I have a HDD and SDD based system I really don't want to have to symlink some directories. I want the OS to handle intelligently putting the data that benefits most on SSD and leave the large data that doesn't require SSD on the HDD.
 
MrXiro

MrXiro

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dasx said:
There are threads on how to create your own. Search for "DIY fusion" and you'll find it. ;)

As for if it's worth it or not… Not in my case. There's been some discussion on the topic and some will tell you it's amazing, I just don't like it. I do understand though it being so useful for the most part of users out there.
Click to expand...

What do you dislike about it?

I'm more worried about data loss than anything. Not that I don't back up my computer but I'd rather not have to deal with the hassle just to end up with 2 crashed drives.
 
dasx

dasx

macrumors 65816
Jun 18, 2012
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Barcelona
MrXiro said:
What do you dislike about it?

I'm more worried about data loss than anything. Not that I don't back up my computer but I'd rather not have to deal with the hassle just to end up with 2 crashed drives.
Click to expand...

Well, a couple of simple examples.

1. Imagine you end this 25GB project. You save it knowing you're gonna be working on it in lets say 3 months and you don't want to just store it. The OS will probably store it in the HDD then therefore you'll have lower speeds when working on it again until the OS realizes you want it in the SSD again and puts it there.

2. I have several virtual machines which I use not too often but a couple of them. If I ran one I haven't used for some time on a Fusion Drive, it'd boot much slower than if I had it stored in an SSD on purpose.

I could add other more subjective reasons, but I don't think they're relevant here.

Again, this is personal. Not for me. I prefer a separate regular HDD and put in it what I want to store there. I don't want the OS to choose for me.
But, as I stated, I do understand it being perfect for the most.

EDIT: It's not its performance what doesn't convince me if that's what you're worried about. ;)

EDIT 2: As for data loss… they haven't been out there too much yet. No one can really tell its failure rate.
(It's assumable though that it'll have a slightly higher failure rate than a single SSD or HDD, as this FD has both therefore if one fails, the whole disk fails)
 
MrXiro

MrXiro

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Original poster
Nov 2, 2007
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Los Angeles
dasx said:
Well, a couple of simple examples.

1. Imagine you end this 25GB project. You save it knowing you're gonna be working on it in lets say 3 months and you don't want to just store it. The OS will probably store it in the HDD then therefore you'll have lower speeds when working on it again until the OS realizes you want it in the SSD again and puts it there.

2. I have several virtual machines which I use not too often but a couple of them. If I ran one I haven't used for some time on a Fusion Drive, it'd boot much slower than if I had it stored in an SSD on purpose.

I could add other more subjective reasons, but I don't think they're relevant here.

Again, this is personal. Not for me. I prefer a separate regular HDD and put in it what I want to store there. I don't want the OS to choose for me.
But, as I stated, I do understand it being perfect for the most.

EDIT: It's not its performance what doesn't convince me if that's what you're worried about. ;)

EDIT 2: As for data loss… they haven't been out there too much yet. No one can really tell its failure rate.
(It's assumable though that it'll have a slightly higher failure rate than a single SSD or HDD, as this FD has both therefore if one fails, the whole disk fails)
Click to expand...

Cool thanks for the info. I'll probably just leave it off. I don't see a reason for me to do it either. If I'm working on a video project it'll be off of an external Firewire drive and I could actually fit all my music, OS and Apps on the SSD right now anyway but would rather keep the music off the main SSD for any future installs.
 
S

SuperRob

macrumors 6502
Mar 14, 2011
253
4
OS X really expects you to have one drive. That's why it doesn't like having applications live on separate drives, doesn't want you to move critical folders, etc. It supports more than that, but from it's own standpoint, it's not ideal. Fusion Drive fits in with how OS X expects your computer to look.

The main drawback is that there is increased risk of hardware failure. You have two potential sources for something to go wrong. If you're going to use Fusion Drive, you MUST backup regularly. As many people don't do this, even when they know they should, this could be considered a major drawback.

The main advantage is that this is the most efficient use of a small SSD possible. You are likely to be a poor judge of what files you read more often than others. And since Fusion Drive works at the block level, it can optimize by having a file spread across both drives to speed access without needing to fill the SSD with the entire file (almost like using the SSD as a buffer of sorts). You're unlikely to achieve the same performance benefit you could get with Fusion Drive on your own, unless your SSD isn't even full.

I should point out that I have a Drobo connected via FireWire 800 that I store all my downloaded software (that hasn't been installed), Movies, TV Shows, and music on. My iTunes library stays on my main drive (Fusion), but the actual media I have configured to live on a different drive. But this is because I have way more media than I could keep on even the largest of laptop drives. :)
 
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dasx

dasx

macrumors 65816
Jun 18, 2012
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18
Barcelona
MrXiro said:
Cool thanks for the info. I'll probably just leave it off. I don't see a reason for me to do it either. If I'm working on a video project it'll be off of an external Firewire drive and I could actually fit all my music, OS and Apps on the SSD right now anyway but would rather keep the music off the main SSD for any future installs.
Click to expand...

I also have a FW drive always connected to my Mini where I store files I don't intend to use for a long period of time. (Or movies, music and other stuff that doesn't need high reading speeds for playback).

Helps me keep much more free space in my SSD so I can just have there what I know I want to use at top speed.
 
M

Mac... nificent

macrumors 6502a
Nov 20, 2012
943
498
MrXiro said:
I'm more worried about data loss than anything. Not that I don't back up my computer but I'd rather not have to deal with the hassle just to end up with 2 crashed drives.
Click to expand...

Both CCC and SuperDuper are looking into adding Fusion backup capability. Should know more in around a month. I hope they can do it (and at this point they both think it's do-able) because I'd love to make a Fusion drive for my Mac. As a side note; I heard that one reason why Apple removed 10.8.2 was because on some computers Disk Utility was creating Fusion drives, and of course Apple wants to sell them not give them away :p
 
T

theanimala

macrumors 6502
Mar 2, 2007
440
228
I'm glad someone started this thread. I am expecting my mini tomorrow along with my 240GB SSD I ordered separately. I was planning on running them separately until I saw that I could make them a fusion drive. I work with IT and have dealt slightly with enterprise storage that auto tiers. I know that systems like that are TOTALLY different, made from the ground up to do this (complex software along with loads of cache, redundant drives, and onsite support to replace failed components quickly). The smarter part of me says to keep things separate, but the tech / guy who wants to get his moneys worth (fusion without paying for fusion) wants to join them together. I have about 12 hours to decide...
 
xlii

xlii

macrumors 68000
Sep 19, 2006
1,867
121
Millis, Massachusetts
A couple of days ago I did a diy fusion drive on my 2012 mac mini. (128gbyte Samsung 830 + 1TB drive. Pretty easy to do if you follow the instructions laid out here and around the web. I think it is great. The risk of data loss does't bother me because I back up my stuff using Time Machine. The good think about it is you can give it a try and if you don't like it you can break it into two separate drives again and restore your data. I have 650gbytes of data on my machine so that 128gbyte drive is full - that 4 gbyte buffer. I have trim installed. Speeds are 300 writes and 400 reads more or less.

When i make by install disk CCC put 35 gbytes of data on it. So that is OSX + Apps + user account data.
 
Fishrrman

Fishrrman

macrumors Penryn
Feb 20, 2009
28,343
12,460
"Been reading a lot about the DIY Fusion drives, wondering if it's actually worth my while to do it or if it's just a high risk task of crashing out the drives and losing all my data one day?"

Since the fusion drive technology was introduced, I've seen little discussion about this. I think it could pose significant problems down the line.

Anyone who uses computers knows that "drives fail". Hard drives are almost destined to fail due to their internal construction with moving platters. Solid-state drives fail as well. So it's reasonable to assume that at some point, a number of fusion drive owners are going to experience some sort of drive failure, either a failure of the hardware or perhaps some kind of directory corruption.

Let's say you have a fusion drive that (up to this point) has been running without problems, and suddenly the hard drive portion of your fusion drive fails.

What next?

Of course, because of fusion, the drive won't mount.

Can the "fusion" be "broken" to "separate" the core volume back into two separate volumes? Even if that can be done, the entire fusion drive (as a "whole") may be unmountable, how will the user "get at it" with Disk Utility, the Terminal, or other software?

Even if the SSD portion can successfully be separated from the HDD portion (which is broken), how might one use data recovery software to access the HDD portion? Will that even be possible?

All kinds of questions yet about fusion, in my mind. Folks are ready to leap into fusion without thinking much about the future.

I sense that without a complete and bootable backup of the fusion drive, meaningful "recovery" in the event of a crash or failure may not be possible. Of course, I keep bootable backups, but the vast majority of users don't. We could see a rash of "fusion failures" something like we see "Time Machine failures" today -- that is, instances where folks have a drive failure, try to restore from Time Machine, and find they can't access their TM backups, etc.

Final thoughts:
The "fusion" concept is Apple's take on "RAID for dummies". Makes multiple-drive management +simple+! That is, until you have a failure, in which things can get VERY complicated very quickly.

If you're not bothered by multiple drive (or partition) management right now, I think the best course of action is to install an SSD and "keep it separate" from the HDD for a while. Let's wait and see how things thrash out when folks start having fusion drives go bad, and see what it takes to recover from such failures....
 
S

SuperRob

macrumors 6502
Mar 14, 2011
253
4
Fishrrman said:
Since the fusion drive technology was introduced, I've seen little discussion about this. I think it could pose significant problems down the line.
Click to expand...

There's been LOTS of discussion about this. The MTBF (mean time between failure) goes down as a result of having two drives involved. Fusion is a convenience / cost saving technology. You still need to have a backup strategy. If a component in the Fusion Drive fails, you can replace the component, rebuild the Fusion Drive, and restore your data. It's no different than having data on any one drive. You would still need to replace the drive, partition and format it, then restore the backup.

Fusion is not "RAID for dummies." Fusion allows you to use a small SSD in the most efficient way possible, while still having access to a large storage device. It shares almost nothing with RAID.
 
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M

Mac... nificent

macrumors 6502a
Nov 20, 2012
943
498
Fishrrman said:
Let's say you have a fusion drive that (up to this point) has been running without problems, and suddenly the hard drive portion of your fusion drive fails.

What next?
Click to expand...

The same could be said for any data storage, that's why God made backups. As soon as SuperDuper gives the green light for backing up a Fusion drive (hopefully within a month) I will make the switch :) There's no reason not to as it will be even safer than traditional drives.
 
MrXiro

MrXiro

macrumors 68040
Original poster
Nov 2, 2007
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Los Angeles
Mac... nificent said:
The same could be said for any data storage, that's why God made backups. As soon as SuperDuper gives the green light for backing up a Fusion drive (hopefully within a month) I will make the switch :) There's no reason not to as it will be even safer than traditional drives.
Click to expand...

I don't think God made Backups... I'm betting it's some electrical engineer or computer technician. :p
 
MrXiro

MrXiro

macrumors 68040
Original poster
Nov 2, 2007
3,850
599
Los Angeles
Fishrrman said:
"Been reading a lot about the DIY Fusion drives, wondering if it's actually worth my while to do it or if it's just a high risk task of crashing out the drives and losing all my data one day?"

Since the fusion drive technology was introduced, I've seen little discussion about this. I think it could pose significant problems down the line.

Anyone who uses computers knows that "drives fail". Hard drives are almost destined to fail due to their internal construction with moving platters. Solid-state drives fail as well. So it's reasonable to assume that at some point, a number of fusion drive owners are going to experience some sort of drive failure, either a failure of the hardware or perhaps some kind of directory corruption.

Let's say you have a fusion drive that (up to this point) has been running without problems, and suddenly the hard drive portion of your fusion drive fails.

What next?

Of course, because of fusion, the drive won't mount.

Can the "fusion" be "broken" to "separate" the core volume back into two separate volumes? Even if that can be done, the entire fusion drive (as a "whole") may be unmountable, how will the user "get at it" with Disk Utility, the Terminal, or other software?

Even if the SSD portion can successfully be separated from the HDD portion (which is broken), how might one use data recovery software to access the HDD portion? Will that even be possible?

All kinds of questions yet about fusion, in my mind. Folks are ready to leap into fusion without thinking much about the future.

I sense that without a complete and bootable backup of the fusion drive, meaningful "recovery" in the event of a crash or failure may not be possible. Of course, I keep bootable backups, but the vast majority of users don't. We could see a rash of "fusion failures" something like we see "Time Machine failures" today -- that is, instances where folks have a drive failure, try to restore from Time Machine, and find they can't access their TM backups, etc.

Final thoughts:
The "fusion" concept is Apple's take on "RAID for dummies". Makes multiple-drive management +simple+! That is, until you have a failure, in which things can get VERY complicated very quickly.

If you're not bothered by multiple drive (or partition) management right now, I think the best course of action is to install an SSD and "keep it separate" from the HDD for a while. Let's wait and see how things thrash out when folks start having fusion drives go bad, and see what it takes to recover from such failures....
Click to expand...

I guess I almost don't see the point of it using Fusion at least in my life... 256gb for an OS and apps is more than enough. I'm never going to have issues with speed of loading music or movies from the HDD anyway. I would never store any video content I am editing locally anyway, so why would I need 1.25tb of storage in a single partition even.
 
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