Re: What does "Reinstall macOS" do, exactly?

On 18/08/2024 23:14, T i m wrote:

On 18/08/2024 22:42, David Brooks wrote:
 <snip>
 

How many folk realise that
reinstalling the macOS will NOT eradicate any previously installed malware?

 Anyone who has a clue re what they are doing around computers.
 See, if you understood what an OS was and what isn't part of the OS (like the personal info you state is still present), what part of it don't you understand?
 If you replace the water feature in your back garden, did you expect all the weeds to disappear as well?
 Cheers, T i m

I've just done this:-
davidbrooks@DavidBs-iMac ~ % diskutil resetFusion
Internally-located hardware disk devices known to the currently-running macOS:
Rotational                               (disk1)
Solid State                              (disk0)
Volumes exported by partitions or storage systems hosted on the above devices:
APPLE SSD SM0128L Media                  (disk0s2)
Storage                                  (disk2s1)
disk0 will be used as the "main" ("faster") device
disk1 will be used as the "secondary" ("larger") device
WARNING: All of the above will be erased
Do you want to continue? (Enter "Yes" to proceed to erase) Yes
Force-unmounting all volumes on the chosen "main" ("faster") disk device
Started on disk0
Finished on disk0
Force-unmounting all volumes on the chosen "secondary" ("larger") disk device
Started on disk1
Finished on disk1
Creating a new partition map on the "main" ("faster") disk device
Started on disk0
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Finished on disk0
Partition disk0s2 will be the "main" ("faster") APFS Physical Store
Creating a new partition map on the "secondary" ("larger") disk device
Started on disk1
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Finished on disk1
Partition disk1s2 will be the "secondary" ("larger") APFS Physical Store
Creating an APFS Fusion Container importing two partitions
Started on disk0s2
Creating a new empty APFS Container
Unmounting Volumes
Switching disk0s2 to APFS
Switching disk1s2 to APFS
Creating APFS Container
FusionLC autodetect: regular Fusion
Created new APFS Container disk2
Finished on disk0s2
The new APFS Container is disk2
Adding a logical APFS Volume to the APFS Container
Started on disk2
Preparing to add APFS Volume to APFS Container disk2
Creating APFS Volume
Created new APFS Volume disk2s1
Mounting APFS Volume
Setting volume permissions
Finished on disk2
The new APFS Volume exported by the APFS Container is disk2s1
Confirmed that your new volume "Macintosh HD" (disk2s1) is a Fusion Drive
Operation successful; you should now install macOS
=
*Complicated, isn't it*? 🙂
I'll list this other information here in case I need it later:-
                        Last login: Sat Jul 12 07:52:32 on ttys001
davidbrooks@DavidBs-iMac ~ % diskutil list
/dev/disk0 (internal, physical):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      GUID_partition_scheme                        *121.3 GB   disk0
    1:                        EFI EFI                     314.6 MB   disk0s1
    2:                 Apple_APFS Container disk2         121.0 GB   disk0s2
/dev/disk1 (internal, physical):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      GUID_partition_scheme                        *2.0 TB     disk1
    1:                        EFI EFI                     209.7 MB   disk1s1
    2:                 Apple_APFS Container disk2         2.0 TB     disk1s2
/dev/disk2 (synthesized):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      APFS Container Scheme -                      +2.1 TB     disk2
                                  Physical Stores disk0s2, disk1s2
    1:                APFS Volume Macintosh HD            819.2 KB   disk2s1
/dev/disk3 (external, physical):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      GUID_partition_scheme                        *1.0 TB     disk3
    1:                        EFI EFI                     209.7 MB   disk3s1
    2:                 Apple_APFS Container disk4         1000.0 GB  disk3s2
/dev/disk4 (synthesized):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      APFS Container Scheme -                      +1000.0 GB  disk4
                                  Physical Store disk3s2
    1:                APFS Volume External HD - Data      461.8 GB   disk4s1
    2:                APFS Volume Preboot                 2.2 GB     disk4s2
    3:                APFS Volume Recovery                1.2 GB     disk4s3
    4:                APFS Volume Macintosh HD (Ext)      9.3 GB     disk4s4
    5:              APFS Snapshot com.apple.os.update-... 9.3 GB disk4s4s1
    6:                APFS Volume VM                      1.1 GB     disk4s6
/dev/disk5 (external, physical):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      GUID_partition_scheme                        *2.0 TB     disk5
    1:                        EFI EFI                     209.7 MB   disk5s1
    2:                 Apple_APFS Container disk6         2.0 TB     disk5s2
/dev/disk6 (synthesized):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:      APFS Container Scheme -                      +2.0 TB     disk6
                                  Physical Store disk5s2
    1:                APFS Volume My Book                 1.9 TB     disk6s2
/dev/disk7 (external, physical):
    #:                       TYPE NAME                    SIZE IDENTIFIER
    0:        CD_partition_scheme                        *804.4 MB   disk7
    1:     Apple_partition_scheme                         700.4 MB   disk7s0
    2:        Apple_partition_map                         32.3 KB disk7s0s1
                     (free space)                         377.3 MB   -
    3:                  Apple_HFS WD SmartWare            320.7 MB disk7s0s2