Et voilà !
Bloc de code:
~ ❯❯❯ diskutil resizeVolume disk2s2 1200g jhfs+ Clone 0b
Resizing to 1200000000000 bytes and adding 1 partition
Started partitioning on disk2s2 Time machine
Verifying the disk
Verifying file system
Volume was successfully unmounted
Performing fsck_hfs -fn -x /dev/rdisk2s2
Checking Journaled HFS Plus volume
Detected a case-sensitive volume
Checking extents overflow file
Checking catalog file
Checking multi-linked files
Checking catalog hierarchy
Checking extended attributes file
Checking multi-linked directories
Checking volume bitmap
Checking volume information
The volume Time machine appears to be OK
File system check exit code is 0
Restoring the original state found as mounted
Resizing
Shrinking file system
Modifying partition map
Initialized /dev/rdisk2s7 as a 243 GB case-insensitive HFS Plus volume with a 24576k journal
Mounting disk
Finished partitioning on disk2s2 Time machine
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *2.0 TB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_HFS Time machine 1.2 TB disk2s2
3: Apple_HFS Clone 260.4 GB disk2s7
4: Apple_HFS Bootable backup 265.3 GB disk2s3
5: Apple_Boot Recovery HD 650.0 MB disk2s4
6: Apple_HFS Install macOS Catalina 273.3 GB disk2s5