diskutil list shows what I am fairly certain is the correct layout. The recovery partition is "outside" the core storage logical volume group on the rotational disk:
% diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk0
1: EFI 209.7 MB disk0s1
2: Apple_CoreStorage 119.7 GB disk0s2
3: Apple_Boot Boot OS X 134.2 MB disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *750.2 GB disk1
1: EFI 209.7 MB disk1s1
2: Apple_CoreStorage 749.3 GB disk1s2
3: Apple_Boot Recovery HD 650.0 MB disk1s3
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS Macintosh HD *865.3 GB disk2
If I mount it, I see:
% ls /Volumes/Recovery\ HD/
System com.apple.boot.P com.apple.recovery.boot
% df -h /Volumes/Recovery\ HD/
Filesystem Size Used Avail Capacity iused ifree %iused Mounted on
/dev/disk1s3 620Mi 500Mi 120Mi 81% 127917 30773 81% /Volumes/Recovery HD
So clearly something's there. Yet, if I hold down option, all I see are the two copies of the fusion drive (does anyone know why home made fusion drives do that and Apple's don't?).
I attempted to
bless -folder /Volumes/Recovery\ HD/System/Library/CoreServices -bootefi /usr/standalone/i386/boot.efi
but that didn't do anything.
I can't help but think that the recovery partition is mostly there and just needs a small "kick" to make it work. I certainly don't think it's worth reinstalling Mountain Lion and restoring from time machine to fix this.
The output of diskutil cs list was requested:
% diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 748D74CE-EBC8-4A7F-985F-239E699255CF
=========================================================
Name: FusionDrive
Status: Online
Size: 868986765312 B (869.0 GB)
Free Space: 0 B (0 B)
|
+-< Physical Volume 2CC32F7C-2358-484C-A885-5757E9AF6CFC
| ----------------------------------------------------
| Index: 0
| Disk: disk1s2
| Status: Online
| Size: 749296615424 B (749.3 GB)
|
+-< Physical Volume 4C8685E8-30DA-41FA-A37D-3BD6E83F9240
| ----------------------------------------------------
| Index: 1
| Disk: disk0s2
| Status: Online
| Size: 119690149888 B (119.7 GB)
|
+-> Logical Volume Family 6A089C96-ACEF-4B36-BF56-7E56C42B1294
----------------------------------------------------------
Encryption Status: Unlocked
Encryption Type: None
Conversion Status: NoConversion
Conversion Direction: -none-
Has Encrypted Extents: No
Fully Secure: No
Passphrase Required: No
|
+-> Logical Volume CD4DEF37-AAA0-4F74-AD1B-A7DE08E3D4CE
---------------------------------------------------
Disk: disk2
Status: Online
Size (Total): 865261846528 B (865.3 GB)
Size (Converted): -none-
Revertible: No
LV Name: Macintosh HD
Volume Name: Macintosh HD
Content Hint: Apple_HFS
Note that the fusion drive itself seems to be working fine. The only difference I can tell in using it between it and a real Apple one is that in the option menu, I see two copies of "Macintosh HD" (both will boot it up). And, of course per this question, no Recovery HD.
Best Answer
Well, I was able to "solve" this in a round-about way.
I used the recovery disk assistant with my MacBook Air to make a recovery SD card. With that plugged into my mini, I was able to successfully boot into it and the disk utility there was able to comprehend my fusion drive.
That done, I then checked and saw that the recovery partition on the SD card was the same size as the recovery partition that wasn't working right, so I did a dd from the SD card overwriting the recovery partition.
The result: my option menu now offers the choice of the fusion drive (booting normally) or the recovery partition, and both work.
What I think may have been going on is that core storage seems to want to turn the recovery partition into a 'boot helper' on encrypted volumes. Perhaps it was trying to do the same thing on this machine, despite the fact that there was a separate boot partition intended to serve that purpose.
I'm not going to mark this as "solved," however, because I think there has to have been a better way.