[SOLVED] Missing or hidden partition and free space on my HDD (Fusion Drive)

[sir_whitelight]

In the past few days I tried to install W10 on a bootcamp made partition. Unfortunately I was unable to, because the error "was unable to create a new system partition..." occurred all the time, so I tried to erase and create the partition via the Windows Installer. Thus many other partitions were made out of the original bootcamp partition (system, msr, windows, recovery). In this way I couldn't use the bootcamp assistant to restore because more than 2 partitions were on the Fusion Drive. So I went back into the windows installer and erased the four partitions all the way back from the last one, resulting in 500 GB of unallocated space that I formatted in ntfs (so that BootC. could see). Unfortunately both BootC. and DiscUtility couldn't see the partition, so the result was that out of a 3TB Fusion Drive, only 2,61 were available. Trying to go back to the windows installer, I made a new bootcamp partition of 48 GB and when I went to the select disk page I saw that the new 48 GB partition had eaten the previous hidden 502 GB, resulting in a BOOTCAMP partition of approximately 550 GB. At this point I was able to go back into BootC. Assistant and remove the BC. part., restoring the full 3 TB capacity.
Now I am doing some further analysis to see if I've actually restored the whole disk, so I'm asking you if you notice anything wrong in this results. In particular if those 17.1 GB of hidden Free Space are a normal value.
Note that FileVault is processing at the time of the Terminal results.
Thanks for the support.

Last login: Thu Jun 28 10:37:16 on console
iMac-di-Mario:~ MarioBoccuto$ diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *121.3 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_CoreStorage Macintosh HD 121.0 GB disk0s2
3: Apple_Boot Boot OS X 134.2 MB disk0s3


/dev/disk1 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *3.0 TB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_CoreStorage Macintosh HD 3.0 TB disk1s2
3: Apple_Boot Recovery HD 650.0 MB disk1s3


/dev/disk2 (internal, virtual):
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS Macintosh HD +3.1 TB disk2
Logical Volume on disk0s2, disk1s2
FDC66B98-A894-4EB7-A197-4477481948E7
Unlocked Encrypted Fusion Drive


iMac-di-Mario:~ MarioBoccuto$ diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 8C98714C-8143-432C-8668-5989EFC48512
=========================================================
Name: Macintosh HD
Status: Online
Size: 3120722075648 B (3.1 TB)
Free Space: 17091903488 B (17.1 GB)
|
+-< Physical Volume 3F707C83-D412-4B13-BAD0-CD67E72F038C
| ----------------------------------------------------
| Index: 0
| Disk: disk0s2
| Status: Online
| Size: 120988852224 B (121.0 GB)
|
+-< Physical Volume 6C7A3848-3B13-4A31-8997-CC7603F0E121
| ----------------------------------------------------
| Index: 1
| Disk: disk1s2
| Status: Online
| Size: 2999733223424 B (3.0 TB)
|
+-> Logical Volume Family 9D4769E5-AE46-4BC3-B43D-B17CDB21AE0D
----------------------------------------------------------
Encryption Type: AES-XTS
Encryption Status: Unlocked
Conversion Status: Converting (forward)
High Level Queries: Not Fully Secure
| Passphrase Required
| Accepts New Users
| Has Visible Users
| Has Volume Key
|
+-> Logical Volume FDC66B98-A894-4EB7-A197-4477481948E7
---------------------------------------------------
Disk: disk2
Status: Online
Size (Total): 3097774915584 B (3.1 TB)
Conversion Progress: 57%
Revertible: No
LV Name: Macintosh HD
Volume Name: Macintosh HD
Content Hint: Apple_HFS
LVG Type: Fusion, Sparse
iMac-di-Mario:~ MarioBoccuto$

[iMac (Retina 5K, 27-inch, Late 2014) with MacOS High Sierra]

 

[xed21]

As MacOS is the native software of the computer, you should only be changing hard drive and partition settings from MacOS and not Windows unless absolutely necessary. Are you able to delete your partition for Windows entirely and start over?

 

[sir_whitelight]

The partition was already erased with the above procedure. I was wondering if any space went lost in the process. Those 17 GB were used by FileVault, now free space is about 115 KB.

 

[xed21]

It’s possible the program you were using for the virtual machine has cached or stored files from running its software. Programs often have saved or cached files which take up some space. As long as you deleted your partition, then you should not have any missing space.

 

[sir_whitelight]

I didn't use any virtual machine, only BootCamp Assistant. The easiest way to verify is by comparing with other Macs using "diskutil cs list" command in Terminal.

 

[xed21]

Even so, saved or cached files by programs or even the system have usually been the culprit for noticed lost space. As long as you don’t see anything unusual (the definition of unusual depends on the person and how they use their computer) by a scan of the hard drive, it seems everything should be fine.

There is of course the nature of how hard drives work contributing to lost space or decreased performance, but that’s just a result of writing and deleting data over the course of time. This is not directly involved with your partition though.

Hopefully this has enlightened you with regards to your question