Caution - Yosemite may screw up partitions.

[GrumpyTrucker]

I entered a bugreport on this a while ago, it was just closed - Apple said this is the way its suppose to work. That is, you ask to have it installed on a partition of a volume, and Apple then changes the type of volume! Unbelievable, and so Microsoftish (well, old MS ways).

I'm stunned!

Anyway, this is what they say to do, to revert: "diskutil cs revert /"

What a crock!

That's just nuts. Not really a lot else to say.

 

[campyguy]

That doesn't make sense. Why would Apple change the way Yosemite installs, especially if all previous versions of OS X didn't install in that fashion? How does it benefit the user and Apple to convert the disk partition layout with this type of installation?

Doing a revert works, and it doesn't seem to affect Yosemite at all, so theoretically, it's not a big deal, but I do wonder why Apple changed the way they deal with disk partition layouts in Yosemite.

This bug and issue aren't new. As I'd written in Post #51, this bug has been around since Lion and has popped up again in 10.8/.9/.10.

What troubles me more about it showing up in 10.10 is that I used to only see it in formatted drives of and over 3TB in size. Now I'm seeing it on my 1TB internal SSD and external drives of 256GB (SSD) and 1TB (platter) - each of them partitioned into two partitions at the time. And, the only means to address this is by using Terminal - which most users could be not inclined to use.

The second item that troubles me - as a small business owner with several Macs running - is that there's no means to manage all of the partitions on a Logical Drive from Disk Utility. That, and AFAIK Logical Drives are allowed two partitions, and no more. I've read, but I don't know, that if one partition in the Logical Group fails, data on both partitions can be lost - when the upgrade comes out, I'll have to test it myself and maybe even perform the installs myself as most of the staff have partitioned drives.

 

[smartalic34]

I agree that you need to erase the Yosemite volume first, but you can't merge the partitions back using GUI Disk Utility. The buttons to modify the drive are greyed out.

This is why you must do it via Terminal. I've tested this three times now and can confirm the same result each time.

Are you doing it with an internal or external drive? I've been able to remerge the partitions with Disk Utility having Yosemite installed on an external disk both times I've attempted it. I didn't touch Terminal.

 

[cardsdoc]

Installed public beta on a second partition on my 2012 RMBP. Same issue as others with logical volume group. I think I'll wait fix it when I install Yosemite as my main OS. However I also noticed that when I boot using option key I only have one recovery partition, just for 10.9. There is no 10.10 recovery partition. Is this expected behavior?

 

[schwinn89]

Installed public beta on a second partition on my 2012 RMBP. Same issue as others with logical volume group. I think I'll wait fix it when I install Yosemite as my main OS. However I also noticed that when I boot using option key I only have one recovery partition, just for 10.9. There is no 10.10 recovery partition. Is this expected behavior?

This fixed that issue for me. After running the commands check for the recovery partition again.

https://forums.macrumors.com/posts/19207476/

 

[Michaelgtrusa]

How to quickly switch between Mavericks and Yosemite beta http://www.idownloadblog.com/2014/07/29/how-to-quickly-switch-between-mavericks-and-yosemite-beta/

 

[Apple_Robert]

How to quickly switch between Mavericks and Yosemite beta http://www.idownloadblog.com/2014/07/29/how-to-quickly-switch-between-mavericks-and-yosemite-beta/

Thanks for the link. I tried it out and it does work. However, when I put in the code to automate the password as directed, it gives me a script error. The following is exactly what I put on the third line of code.

do shell script "bless -device /dev/" & deviceID & ¬
" -setBoot -nextonly" password <mypasswordhere> with administrator privileges

 

[OcelotWreak]

Clarification on diskutil commands...

Two Terminal commands assessed and fixed the issue for me in about 10 seconds:

1. First, the "diskutil cs list" command yielded two critical pieces of information - that the volume was Revertible and the lvUUID of the volume I wanted to revert. I have always used the last lvUUID for the next step.
2. Second, the "diskutil coreStorage revert lvUUID" (where lvUUID is that reported by the previous Terminal command) restored both partitions to the Mac OS Extended (Journaled) format that I'd set them up with.

...

Just to clarify, for those of us who are not UNIX wizards, the second command containing the UUID string is not prefixed with "lv" before the actual UUID string (e.g., it should be entered as:

diskutil coreStorage revert 69ABA4B8-A4C1-4180-A3A9-5EC85EB41758

[using whatever the actual string value is from your Yosemite system logical volume]

NOT

diskutil coreStorage revert lv69ABA4B8-A4C1-4180-A3A9-5EC85EB41758

which is what I did at first. [I am a literal man, not a smart man.])

Obviously you will get an error msg "Unable to find disk for lv69ABA4B8-A4C1-4180-A3A9-5EC85EB41758" if you prefix it with lv.

*sigh*
-ocelot.

 

[campyguy]

Just to clarify, for those of us who are not UNIX wizards, the second command containing the UUID string is not prefixed with "lv" before the actual UUID string (e.g., it should be entered as:

diskutil coreStorage revert 69ABA4B8-A4C1-4180-A3A9-5EC85EB41758

[using whatever the actual string value is from your Yosemite system logical volume]

NOT

diskutil coreStorage revert lv69ABA4B8-A4C1-4180-A3A9-5EC85EB41758

which is what I did at first. [I am a literal man, not a smart man.])

Obviously you will get an error msg "Unable to find disk for lv69ABA4B8-A4C1-4180-A3A9-5EC85EB41758" if you prefix it with lv.

*sigh*
-ocelot.

Pick on Apple, not me. As I'd written earlier, those commands were unpublished for many years and only recently have shown up in the BSD Manual.

So, for further clarification - lvUUID represents "logical volume Universally Unique Identifier". The first command is a query that returns a text string not prefaced by "lv" - the technical writer in me would have included the added "lv" before the text string if it were required. I also referred followers of this and another thread to the BSD Manual. So, cite that. I was trying to be helpful. FWIW, I'm a civil engineer more comfortable with planners and surveyors, not an IT person.

 

[ECONORAM]

my install experience with Yosemite

Have lurked for a while off and on, but after installing Yosemite and scratching my head at the boot menu results, I found this thread at MacRumors and registered. I'm not a super-knowledgeable Mac-type by any stretch, but here's what I encountered with my install.

Signed up for the beta and finally got the email. Heeded advice from LifeHackers, and created a (third) partition for Yosemite on my drive. I was dual-booting Snow Leopard and Mavericks prior to this. Followed the link and redeemed the code and zip. Nothing. Took a few days to learn there was a purchased button on the App Store, and that's where the download button was. So, off we went.

Downloaded the file AND read the EULA (I'm paranoid that way), then installed. Things seemed to go fine, through 2 reboots until after the dust settled and Yosemite was up and running. (Oooo, Ahhh) However, I wanted to boot back into my Mavericks install instead of re-entering all my user data for iMessage and such into Yosemite. Tried using the option button on boot up and got these 5 options: Macintosh 2 (Snow Leopard), OS X Installer, Recovery 10.9, Yosemite and Recovery 10.10. Well, this was rather disturbing. When booting into Yosemite, and going to the Disk Utility, I could see the three partitions. Ran the repair disk on Mavericks and repair permissions, which did clean some stuff up, but the 5 options were the same at the boot menu.

Did more research and some folks said two files starting with .AI or something similar in the boot portion of the drive were causing the issue, and you had to get Finder to unhide the files so you could find and delete them. Well, couldn't figure out how to unhide the files, so that bombed.

Also did some searching on Core Storage/Fusion Drive, but learned that didn't apply in my case.

I did notice in Disk Utility that when the mouse hovered over the Yosemite disk, it said start-up disk; the others said mounted partition. That got me thinking about how, when I partitioned the drive, I had designated the Snow Leopard drive initially as my startup drive in System Preferences. So, I went into System Preferences, Startup Disk and selected Mavericks to be the startup. Held my breath....rebooted, and VOILA! Mavericks boots up. So, then I quit the OS X 10.10 Installer,...which was still up and waiting until this point, and reboot again. Used option and the boot menu was as it should be: Macintosh 2, Mavericks, Recovery 10.9, Yosemite and Recovery 10.10.

 

[Weaselboy]

So, I went into System Preferences, Startup Disk and selected Mavericks to be the startup. Held my breath....rebooted, and VOILA! Mavericks boots up. So, then I quit the OS X 10.10 Installer,...which was still up and waiting until this point, and reboot again. Used option and the boot menu was as it should be: Macintosh 2, Mavericks, Recovery 10.9, Yosemite and Recovery 10.10.

Ran across this article today describing your exact issue and it shows the fix you discovered.

 

[chrisrand]

I know this is an old article, but this recently happened to me and the easiest way to get rid of the Yosemite partition is to:

1) Boot your other OS, mine was Mavericks
2) Open Disk Utility
3) Select the Yosemite partition
4) Select the erase tab, erase it,
5) Select the main drive and go to the partition tab, where you can then delete the Yosemite partition and resize it back to the original size.

Hope that helps!

 

[David9999]

Unable to delete partition

Hi Guys,
I installed Yosemite on a separate partition on my Mini hard drive but now I cannot delete the partition. 'Diskutil cs list' reports "No CoreStorage logical volume groups found". 'Diskutil list' shows the Yosemite partition as 'disk0s4'.

When I try to use Disk Utility to delete the partition the system responds "Partition failed with the error: Requested size change for target disk is too small. Please try a different disk or partition, or make a larger change."

Any thoughts on how to remove this partition?

Thanks,
David

 

[Weaselboy]

Hi Guys,
I installed Yosemite on a separate partition on my Mini hard drive but now I cannot delete the partition. 'Diskutil cs list' reports "No CoreStorage logical volume groups found". 'Diskutil list' shows the Yosemite partition as 'disk0s4'.

When I try to use Disk Utility to delete the partition the system responds "Partition failed with the error: Requested size change for target disk is too small. Please try a different disk or partition, or make a larger change."

Any thoughts on how to remove this partition?

Thanks,
David

Try a command-r boot to recovery and from there use Disk Util to first erase the Yosemite partition then after that remove it.

While you are there click the Apple and select Mavs back as your startup volume.

 

[David9999]

Thanks. CMD-R and Erase partition no problem. Delete partition results in exactly the same 'Partition failed' error.

David

 

[Weaselboy]

Thanks. CMD-R and Erase partition no problem. Delete partition results in exactly the same 'Partition failed' error.

David

Does a verify disk run show any errors?

 

[David9999]

No errors.

 

[Weaselboy]

No errors.

Can you post the output of diskutil list and also a screenshot of Disk Util.

Confirm diskutil cs list still shows no core storage volumes?

 

[David9999]

Disk Util:

Last login: Tue Aug 12 08:20:52 on console
davids-mac-mini:~ arnolda001$ diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *320.1 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 288.7 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Apple_HFS Yosemite 29.8 GB disk0s4
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *2.0 TB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_HFS Back-ups 2.0 TB disk1s2
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_HFS Back-ups 1 999.9 GB disk2s2
/dev/disk3
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *3.0 TB disk3
1: EFI EFI 314.6 MB disk3s1
2: Apple_HFS Master Fotos, Music ... 3.0 TB disk3s2

davids-mac-mini:~ arnolda001$ diskutil cs list
No CoreStorage logical volume groups found
davids-mac-mini:~ arnolda001$

Attached is the screenshot.

David

 

[Weaselboy]

Disk Util:

Last login: Tue Aug 12 08:20:52 on console
davids-mac-mini:~ arnolda001$ diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *320.1 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 288.7 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Apple_HFS Yosemite 29.8 GB disk0s4

Odd.

Try running this command in Terminal. If it won't work, try it from Terminal in recovery. Once in recovery you can launch Terminal from the Utilities menu.

diskutil eraseVolume HFS+ Blank /dev/disk0s4

 

[David9999]

Worked without the need to go to Recovery mode:

diskutil eraseVolume HFS+ Blank /dev/disk0s4
Started erase on disk0s4 Yosemite
Unmounting disk
Erasing
Initialized /dev/rdisk0s4 as a 28 GB case-insensitive HFS Plus volume
Mounting disk
Finished erase on disk0s4 Blank

as you'll see from the screenshot.

However the system still won't let me delete the partition.

 

[Weaselboy]

Worked without the need to go to Recovery mode:

diskutil eraseVolume HFS+ Blank /dev/disk0s4
Started erase on disk0s4 Yosemite
Unmounting disk
Erasing
Initialized /dev/rdisk0s4 as a 28 GB case-insensitive HFS Plus volume
Mounting disk
Finished erase on disk0s4 Blank

as you'll see from the screenshot.

However the system still won't let me delete the partition.

Hmmm... is your system new enough that is has Internet recovery (this or newer)?

If so, try going to Internet recovery by holding command-option-r at boot. You will get a spinning globe while the recovery url downloads. Once it comes up try Disk Util from there to first do a repair disk on the while drive then try removing that partition.

 

[David9999]

Yes, it did allow for Internet Recovery. Repair disk first - no errors reported. Next tried to delete the partition but again it failed. This time the error message was much shorter, simply - partition size too small.

David

 

[Weaselboy]

Yes, it did allow for Internet Recovery. Repair disk first - no errors reported. Next tried to delete the partition but again it failed. This time the error message was much shorter, simply - partition size too small.

David

Do you have a good Time Machine backup of the Mavericks partition? You could option key boot to the TM backup disk then use Disk Util to erase the entire disk by going to the erase tab and selecting the disk itself at the very top above Macintosh HD then formatting the whole disk to Mac OS Extended (Journaled). Then quit Disk Util and restore.

Beyond this nuclear option, I am out of ideas to get that darn thing removed.

 

[David9999]

I sort of guessed this was coming. I've a good TM back-up but just to be sure I started making a Clone about an hour ago. Looks like tomorrow I'll be trashing what currently exists and re-installing.

My thanks for all your efforts, I've really appreciated the time you've taken.

David