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Issue Creating a 2nd Partition on Fusion Drive

M

marc.garcia

macrumors regular
Jul 26, 2010
131
2
Hello there and many many thanks for your response. I appreciate your effort and I thank you for taking the time to answer from your iPhone. It has taken me a little while because yesterday I gave it a go but did not manage to solve the problem, but today I've successfully solved it! :)

jedib0p said:
Are you using an official fusion drive? If so, remove the second volume using disk utility app (GUI. Not the command line version). You may need to boot the recoveryHD or a USB mountain lion disk to do this. I believe all the disk space should be recovered on completion.
Click to expand...

It is indeed an official fusion drive. I don't have good experience with GUI and partitions. When I added the second partition I ended up with an extremely large partition. When I attempted to remove that partition (I was not in Recovery Mode), the system started displaying error messages and stuff.... I've tried to remove the partition in Recovery Mode and everything turned out just fine.

There shouldn't be any free space and your fusion drive should be its original size.
Click to expand...

I don't think the fusion drive reverts to its original state. I had to run different
Code: 
 diskutil cs resizeStack
and
Code: 
 diskutil cs resizeVolume
. In the end it turned out fine.

Using
Code: 
diskutil list
Discover the size of the apple_corestorage on disk1. It is from this size that you will reduce to create a 2nd volume. (At this moment disk0s2 and disk1s2 should be adding up to the total of the LVG)
Click to expand...

After trying many alternatives, and this is the thing that has taken me most of the time I had to invest into this, I've managed to pull the Fusion Drive so it covers the two Physical Volumes. In case anybody is having the same problems, by using
Code: 
diskutil cs resizeVolume 9700F74E-832F-4214-962C-037D44085D5D xT
I managed to minimize the Free Space (or space that for some reason has not been assigned to the Fusion Drive - see my previous post). The bad news is that there is no such a flag which will automatically determine the size one has to set in order to maximize the available space, or at least not one that I know... Finally I managed to use up almost all the space leaving only 80KB behind (before more than 11GB where at stake), which is exactly what bothered me the last time I wrote.

In order to ensure the operation uses all the available space I would suggest using a larger fusion drive size than you had calculated in the command. It will give you an error if there isn't enough space. Just reduce the value by 1 until the command runs. For me my final fusion size was 991G and I started at 997G until the command ran.
Click to expand...

Yes, that's exactly what I meant. Command line is by default not user friendly, but doing binary calculations while fumbling around with partitions is annoying. For the record, one can do
Code: 
 echo $((value1 - value2))
in the command line. That will do the math for you and help you chose the most accurate value.

I hope this is legible. It's really hard writing a post on an iPhone.
Click to expand...

Again, I really appreciate your effort and thank you for being the light house here!

I'm so glad I've managed to finally place my iPhoto Library in a volume, in which permissions are ignored, and I can share the Library with my wife securely (https://discussions.apple.com/thread/4285461?start=30&tstart=0) and avoiding external drives or disk images (see http://support.apple.com/kb/HT1198?viewlocale=en_US&locale=en_US).

Thanks agian,

Marc

PS:... and I insist, Apple should really reconsider its take on some aspects. Many things are great and work great, but there are a few things (like this one for example) that defeat the whole "it just works" concept. Come on, I don't buy that in the XXI century iPhoto is still designed as a single user application...
 
marzer

marzer

macrumors 65816
Nov 14, 2009
1,398
123
Colorado
jedib0p said:
Here's the output from the diskutil command:

diskutil coreStorage resizeStack lvUUID [pvUUID] size
[part1Format part1Name part1Size part2Format part2Name part2Size
part3Format part3Name part3Size ...]

the lvUUID I think was the last number that comes up when you do a "diskutil cs list" (it may have been the LVG UUID but if you put the wrong one it will just give an error and you can change it to the correct one). The pvUUID is an optional command to specify which physical disk is reduced when the command is carried out. This is useful to insure the space is resized on the HDD rather than the SSD.

In my case my original Fusion Drive was 1.12TB and I wanted to create a partition that was 120GB on the HDD (turning the fusion into roughly 1.0TB). I basically compared the sizes from the diskutil list command to determine what the before and after sizes should be.

Here's a screenshot to show you what numbers I used.

Obviously you would need to use your own UUIDs but here's what my command looked like:

Code: 
diskutil cs resizeStack B76211F4-4A5B-44FB-AC5B-8CCE361CADA2 CC0F89BF-4A19-4442-B273-933AF6D772C1 991G jhfs+ Media 120G

991G is the size I want my Fusion Drive to be post operation.
"jfhs+ Media 120G" specifies I want to create a 120GB journaled HFS+ volume named Media.

I'm going from memory here but hopefully that is clear enough for you.
Click to expand...

Thanks. This is good stuff. I've been able to add additional partitions to my fusion drive.

Unfortunately I've not been able to maintain a Windows installation. If I install Windows first with Boot Camp and then add the additional partitions, the Windows partition becomes unbootable. If I add additional partitions first and then try to install Windows, Windows install is unable to install to any partition on the drive. Have you had any success booting Windows with a multi-partitioned Fusion drive?
 
J

jedib0p

macrumors member
Original poster
Sep 15, 2006
35
3
Canada
marzer said:
Thanks. This is good stuff. I've been able to add additional partitions to my fusion drive.

Unfortunately I've not been able to maintain a Windows installation. If I install Windows first with Boot Camp and then add the additional partitions, the Windows partition becomes unbootable. If I add additional partitions first and then try to install Windows, Windows install is unable to install to any partition on the drive. Have you had any success booting Windows with a multi-partitioned Fusion drive?
Click to expand...

I haven't tried. I rarely use Windows and when I do Parallels is a better solution for me.
 
M

marc.garcia

macrumors regular
Jul 26, 2010
131
2
Has anybody who has partitioned the FD updated to Mavericks? If so, have you had any trouble with this custom partition?
 
M

marc.garcia

macrumors regular
Jul 26, 2010
131
2
marc.garcia said:
I'm so glad I've managed to finally place my iPhoto Library in a volume, in which permissions are ignored, and I can share the Library with my wife securely (https://discussions.apple.com/thread/4285461?start=30&tstart=0) and avoiding external drives or disk images (see http://support.apple.com/kb/HT1198?viewlocale=en_US&locale=en_US).

Thanks agian,

Marc

PS:... and I insist, Apple should really reconsider its take on some aspects. Many things are great and work great, but there are a few things (like this one for example) that defeat the whole "it just works" concept. Come on, I don't buy that in the XXI century iPhoto is still designed as a single user application...
Click to expand...

Guys, I've noticed something worth mentioning. The pictures contained in my last two imported photostreams (I have iPhoto configured so it will import all of our photostreams) were half corrupted when I opened iPhoto yesterday. I did the math and I immediately looked towards Mavericks which was released on Oct the 22nd...

Guess what? On my second partition the "Ignore ownership on this volume" had been unchecked!!!! I find it hard to find an explanation for this, and I'm sure nobody has manually and consciously changed that.

What I did? I removed the library (glups!!!), checked the aforementioned flag and recovered a version of my library dated a while before I upgrade to Mavericks. Now every user must go to Preferences, uncheck and check Photostream back.

Can anybody confirm this? If somebody does, I will proceed on to provide negative feedback to Apple... Man, I may change my mind regarding application automatic updates!
 
Jayboard

Jayboard

macrumors newbie
Oct 17, 2015
2
1
Great thread. Thanks to the OP from way back. This (Disk Utility creating a partition that's much bigger than you specified) is still a problem in 2015, on Yosemite 10.10.5 and late 2013 21.5 inch iMac. I only wanted about a 40 GB partition for a sandbox and got 141 GB instead using Disk Utility. This procedure gave me exactly what I wanted. Thanks!
 
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M

MrBlJmp

macrumors newbie
Mar 16, 2016
1
0
Hi there, I am having the same problem on my Late 2012 iMac.

Disk Utility created a 185.8 GB instead of 35 GB for a Windows XP installation.

So I tried this;

Code: 
diskutil cs resizeStack lvUUID pvUUID 1076G fat32 BOOTCAMP 35G

However, I always got the same error;

Error: -69771: The target disk is too small for this operation

Though I even reduced the fusion size to 1000 GB!

Can anyone fix the problem?

PS: OS is Yosemite 10.10.5.
 
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