Comprobación cruzada inconsistente en la partición HFS +, no se puede reparar

Tengo un disco duro de 1 TB con dos particiones encriptadas, una para cosas aleatorias y otra para la copia de seguridad de Time Machine.

Al reorganizar algunos datos, ejecuté una comprobación de la Utilidad de Disco.

Aparentemente, la partición de Time Machine estaba dañada, la utilidad del disco me dijo que ejecutara el S.O.S desde la unidad de recuperación, pero no funcionó.

Esta es la salida de diskutil list /dev/disk2 :

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:          Apple_CoreStorage Backup                  499.9 GB   disk2s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk2s3
   4:          Apple_CoreStorage Data                    499.8 GB   disk2s4
   5:                 Apple_Boot Boot OS X               134.2 MB   disk2s5

Y la salida de sudo fsck_fs /dev/disk2s2 :

   Executing fsck_cs (version 546)
** Checking volume
** disk2s2: Scan for Volume Headers
** disk2s2: Scan for Disk Labels
** Logical Volume Group 9438339C-2B92-48CE-A671-112C7D7ED26C on 1 device
** disk2s2: Scan for Metadata Volume
** Logical Volume Group has a 24 MB Metadata Volume with double redundancy
** Start scanning metadata for a valid checkpoint
** Load and verify Segment Headers
** Load and verify Checkpoint Payload
** Load and verify Transaction Segment
** Incorporate 0 newer non-checkpoint transactions
** Load and verify Virtual Address Table
** Load and verify Segment Usage Table
** Load and verify Metadata Superblock
** Load and verify Logical Volumes B-Trees
** Logical Volume Group contains 1 Logical Volume
** Load and verify 8BA6B22C-6BEC-4F31-9F8E-2DE15736B7FC
** Load and verify 1C2D8BDD-2097-420D-B07E-57237492C1B0
** Load and verify Freespace Summary
** Load and verify Block Accounting
   Unable to bootstrap transaction group 4124: inconsistent crosscheck
Invalidate transaction group? NO
** Continue scanning metadata for an older checkpoint
** Load and verify Segment Headers
** Load and verify Checkpoint Payload
** Load and verify Transaction Segment
** Incorporate 0 newer non-checkpoint transactions
** Load and verify Virtual Address Table
** Load and verify Segment Usage Table
** Load and verify Metadata Superblock
** Load and verify Logical Volumes B-Trees
** Logical Volume Group contains 1 Logical Volume
** Load and verify 8BA6B22C-6BEC-4F31-9F8E-2DE15736B7FC
** Load and verify 1C2D8BDD-2097-420D-B07E-57237492C1B0
** Load and verify Freespace Summary
** Load and verify Block Accounting
   Unable to bootstrap transaction group 4123: inconsistent crosscheck
Invalidate transaction group? NO
** Continue scanning metadata for an older checkpoint
** Load and verify Segment Headers
** Load and verify Checkpoint Payload
** Load and verify Transaction Segment
** Incorporate 0 newer non-checkpoint transactions
** Load and verify Virtual Address Table
** Load and verify Segment Usage Table
** Load and verify Metadata Superblock
** Load and verify Logical Volumes B-Trees
** Logical Volume Group contains 1 Logical Volume
** Load and verify 8BA6B22C-6BEC-4F31-9F8E-2DE15736B7FC
** Load and verify 1C2D8BDD-2097-420D-B07E-57237492C1B0
** Load and verify Freespace Summary
** Load and verify Block Accounting
   Unable to bootstrap transaction group 4122: inconsistent crosscheck
Invalidate transaction group? NO
** Continue scanning metadata for an older checkpoint
** Load and verify Segment Headers
** Load and verify Checkpoint Payload
** Load and verify Transaction Segment
** Load and verify Transaction Segment
** Load and verify Transaction Segment
** Load and verify Transaction Segment
** Load and verify Transaction Segment
** Incorporate 4 newer non-checkpoint transactions
** Load and verify Virtual Address Table
** Load and verify Segment Usage Table
** Load and verify Metadata Superblock
** Load and verify Logical Volumes B-Trees
** Logical Volume Group contains 1 Logical Volume
** Load and verify 8BA6B22C-6BEC-4F31-9F8E-2DE15736B7FC
** Load and verify 1C2D8BDD-2097-420D-B07E-57237492C1B0
** Load and verify Freespace Summary
** Load and verify Block Accounting
   Unable to bootstrap transaction group 4117: inconsistent crosscheck
Invalidate transaction group? NO
   No valid commit checkpoint found
** The volume 9438339C-2B92-48CE-A671-112C7D7ED26C was found corrupt and needs to be repaired

Aquí se sugiere deshabilitar el cifrado, verificarlo, volver a activarlo y here sugiere el uso de repairDisk (sin embargo, no estoy seguro si es la forma correcta ya que el error es un es diferente y el comando dice que una partición puede borrarse mientras se repara el mapa de partición).

Parece extraño ya que acababa de borrar la partición ayer para reiniciar la máquina del tiempo desde cero. ¿Cuál podría ser la mejor manera de proceder?

EDITAR: Corrí sudo diskutil repairDisk /dev/disk2 pero obtengo (sintetizado):

The volume 9438339C-2B92-48CE-A671-112C7D7ED26C was found corrupt and needs to be repaired
Storage system check exit code is 1
Problems were encountered during repair of the partition map
Error: -69716: Storage system verify or repair failed
Underlying error: 1: Operation not permitted

9438339C-2B92-48CE-A671-112C7D7ED26C es de hecho la partición de Time Machine.