Very weird problem: Too many hidden partitions, can't repartition!

[Mithalogica]

OK, my HD is.... "messed up" may be putting it mildly. (Specs: iMac 27-inch late 2012, Mavericks 10.9.5, 8GB/1TB)

I seem to have 8 total partitions, including several hidden partitions on my drive that I did not create. Two are "EFI," two are "Macintosh HD," along with "Boot OS X," and the expected "Recovery HD." As below:

This came to my attention while trying to install BootCamp, which I was able to do successfully, as you can see. However, the extra drives seemed odd, especially since I get three (3?!) EFI drives showing up on my desktop briefly on reboot. (One of these may for my cloned copy of my drive? The items below "Manor" are all proper external USB drives, except for BootCamp.)

(Full disk util list and diskutil cs list results posted HERE on the Apple Forum) , so I won't duplicate them here (I can if desired, of course!).

Things have been working fine, despite the oddness, so it wasn't a problem until I realized every restart now defaults to the Windows partition. I assumed I had left it that way in the System Prefs, but when I went to change it, I got this:

I can boot into OS X, but only if I shut down and restart with the Option key and select the main OS X HD at the boot volume.

My thought of course, was to wipe the whole thing and start over. I am thoroughly backed up, and am willing and able to nuke the entire drive and ALL its partitions BUT Disk Utility won't let me. Under no set of circumstances I have tried (external drive boot, OS X DVD, or Recovery Mode) am I able to repartition the drive; the options to do so are greyed out.

I have seen some *similar* issues with Yosemite, but I haven't touched Yosemite, and I have yet to see this many extra partitions. AND, none of them list as 'revertible.'

Help?

 

[Mithalogica]

More details

Was asked to post these on the Apple forum, so I though I'd include them here; maybe they will help:


sudo gpt -vv -r show /dev/disk0
gpt show: /dev/disk0: mediasize=121332826112; sectorsize=512; blocks=236978176
gpt show: /dev/disk0: PMBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 236978175
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 236306352 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
236715992 262144 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
236978136 7
236978143 32 Sec GPT table
236978175 1 Sec GPT header


sudo fdisk /dev/disk0
Disk: /dev/disk0 geometry: 14751/255/63 [236978176 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: EE 1023 254 63 - 1023 254 63 [ 1 - 236978175] <Unknown ID>
2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

sudo gpt -vv -r show /dev/disk1
gpt show: /dev/disk1: mediasize=1000204886016; sectorsize=512; blocks=1953525168
gpt show: /dev/disk1: Suspicious MBR at sector 0
gpt show: /dev/disk1: Pri GPT at sector 1
gpt show: /dev/disk1: Sec GPT at sector 1953525167
start size index contents
0 1 MBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 1317547968 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
1317957608 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1319227144 248
1319227392 634296320 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
1953523712 1423
1953525135 32 Sec GPT table
1953525167 1 Sec GPT header

sudo fdisk /dev/disk1
Disk: /dev/disk1 geometry: 121601/255/63 [1953525168 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>
2: AC 1023 254 63 - 1023 254 63 [ 409640 - 1317547968] <Unknown ID>
3: AB 1023 254 63 - 1023 254 63 [1317957608 - 1269536] Darwin Boot
*4: 07 1023 254 63 - 1023 254 63 [1319227392 - 634296320] HPFS/QNX/AUX

 

[alex0002]

This came to my attention while trying to install BootCamp, which I was able to do successfully, as you can see. However, the extra drives seemed odd, especially since I get three (3?!) EFI drives showing up on my desktop briefly on reboot. (One of these may for my cloned copy of my drive? The items below "Manor" are all proper external USB drives, except for BootCamp.)

The orange EFI icon will be a USB drive.

(Full disk util list and diskutil cs list results posted HERE on the Apple Forum) , so I won't duplicate them here (I can if desired, of course!).

Your apple forums link appears to be broken. This should be the correct one.
https://discussions.apple.com/thread/6804250

You appear to have both a fusion drive and bootcamp. Bootcamp uses an Hybrid MBR which tries to present a GUID partitioned disk (gpt) to OS X and an MSDOS/FDISK partitioned disk to Windows. Bad things can happen when the information in gpt and fdisk gets out of sync.

If it were me I'd wipe everything and recover from backups. If you want to continue using a fusion drive, you'd have to rebuild during the recovery process.

 

[grahamperrin]

… this: …

For search purposes, the following words appear in that screenshot:

----

You can't change the startup disk to the selected disk.

Building boot caches on boot helper partition failed.​

----

I have seen that symptom without Fusion Drive, without Boot Camp. Later today I'll have access to the drive where records of that incident are stored.

In the meantime, don't rush to erase any file system or partition table.

First, simply reset the NVRAM. In Apple Support: How to Reset NVRAM on your Mac

Reference, in Stack Exchange, the accepted answer to Can not set startup disk.

Rewind, to other mentions in MacRumors Forums:

Building boot caches” error when changing startup disk (2011-08-07)

… "building boot caches on boot helper partition failed". …

Elsewhere, later that month, from the same poster:

… "building boot caches on boot helper partition failed". …

[Guide] Success! Install 10.8 on old unsupported Mac (2012-02-17) – Boot caches (2013-03-31)

… "Building boot caches on boot helper partition failed" …

Fast forward, to the present:

… https://discussions.apple.com/thread/6804250 …

Thanks. From that topic:

----

"…

/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage                         121.0 GB   disk0s2
   3:                 Apple_Boot Boot OS X               134.2 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_CoreStorage                         999.3 GB   disk1s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Manor                  *1.1 TB     disk2

This all started when trying to set up BootCamp, which also threw up a list of 7 volumes, none of which could be used to install Windows."​

----

"…

CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 4595DA22-0057-4CBE-A0A2-2E64596FAF8F
    =========================================================
    Name:         Macintosh HD
    Status:       Online
    Size:         1120333979648 B (1.1 TB)
    Free Space:   114688 B (114.7 KB)
    |
    +-< Physical Volume 11DB863A-1C0B-4B94-9E8C-1544FBB1F5A2
    |   ----------------------------------------------------
    |   Index:    0
    |   Disk:     disk0s2
    |   Status:   Online
    |   Size:     120988852224 B (121.0 GB)
    |
    +-< Physical Volume C1885864-73C5-421D-A586-8FDA851C638B
    |   ----------------------------------------------------
    |   Index:    1
    |   Disk:     disk1s2
    |   Status:   Online
    |   Size:     999345127424 B (999.3 GB)
    |
    +-> Logical Volume Family 1FE488FF-14E6-4A4D-9A80-1A8FD336A190
        ----------------------------------------------------------
        Encryption Status:       Unlocked
        Encryption Type:         None
        Conversion Status:       NoConversion
        Conversion Direction:    -none-
        Has Encrypted Extents:   No
        Fully Secure:            No
        Passphrase Required:     No
        |
        +-> Logical Volume 77D2C79F-AFAB-4E79-B0A4-E1E7F07F5D8F
            ---------------------------------------------------
            Disk:                  disk2
            Status:                Online
            Size (Total):          1111826497536 B (1.1 TB)
            Conversion Progress:   -none-
            Revertible:            No
            LV Name:               Manor
            Volume Name:           Manor
            Content Hint:          Apple_HFS

…"​

----

"I have gotten BootCamp to behave, but I still have an excess of hidden partitions. Except when they're not hidden.

Because this is what happens when I reboot:

'Manor' is the primary internal Mac Boot drive, BootCamp is well, BootCamp, partitioned off the internal drive. 'Archive, 'Warehouse,' and 'Carbon Copy' are all external USB drives. It's the three EFI beasties I'm concerned with! I can understand having one for the internal drive, and maybe one for BootCamp. But three? And should they be showing up like this? They all vanish after a few seconds, but I'm thinking this is not supposed to be a thing? There are still two hidden partitions called 'Macintosh HD' that don't mount on reboot, but are still lurking there. …"​

----

Related

What techniques for disk, volume and file system management are possible with OS X, but troublesome within Disk Utility?

Also, a few months ago there was something extraordinary, in MacRumors Forums, about Disk Utility misrepresentation of things. The search features might not easily find that post, but I'll try …

 

[Mithalogica]

Tried everything...

I tried the NVram, I even tried Cmd-Opt-P-R, just for nostalgia. Nothing worked. I ultimately did reboot from internet recovery, and used cs diskutil to destroy the whole she-bang, rebuild the LVG and each LV.

The EFIs still flash into view at start-up, but they vanish almost immediately, and I can set the Mac volume to boot, so I'm calling it a win.

Not so impressed with the Fusion Drive; seems like a bit if a fussy old thing, but mine seems to be working again, so...all's well that ends well, yeah?

Thanks for the input here; much appreciated!