I have a hard drive dedicated for Time Machine backups and recently I decided to split the partition into 2. The second one became storage for a disk image of my main drive (in case my Hackintosh update fails). What bothered me was that every time I connected my Time Machine drive, the second partition got connected as well. How to prevent that?
Disclaimer: Proceed with caution and on your own risk.
First, we have to find out, what is the Disk identifier:
diskutil list
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.1 GB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_CoreStorage Time Machine 349.9 GB disk2s2
3: Apple_Boot Boot OS X 134.2 MB disk2s3
4: Microsoft Basic Data Stash 149.7 GB disk2s4
The volume in question is called Stash and its Disk identifier is disk2s4. Now we have to get the Volume UUID:
diskutil info /dev/disk2s4
Device Identifier: disk2s4
Device Node: /dev/disk2s4
Whole: No
Part of Whole: disk2
Volume Name: Stash
Mounted: No
Partition Type: Microsoft Basic Data
File System Personality: ExFAT
Type (Bundle): exfat
Name (User Visible): ExFAT
OS Can Be Installed: No
Media Type: Generic
Protocol: USB
SMART Status: Not Supported
Volume UUID: 7727ED95-7E4C-3A6F-A25C-79F2D5F0721B
Disk / Partition UUID: D2A8FB28-2F27-4BEA-990A-D94A3691FA5D
Partition Offset: 350241161216 Bytes (684064768 512-Byte-Device-Blocks)
Disk Size: 149.7 GB (149732458496 Bytes) (exactly 292446208 512-Byte-Units)
Device Block Size: 512 Bytes
Volume Total Space: 0 B (0 Bytes) (exactly 0 512-Byte-Units)
Volume Free Space: 0 B (0 Bytes) (exactly 0 512-Byte-Units)
Read-Only Media: No
Read-Only Volume: Not applicable (not mounted)
Device Location: External
Removable Media: Fixed
Solid State: Info not available
The only thing left is to disable auto mount. For that we have to call sudo vifs as it is recommended to alter fstab using vifs.
If you are not familiar with vi program, DO NOT PROCEED. Find some tutorial first and when you are comfortable with it, come back and continue.
There we have to enter line like this:
UUID=7727ED95-7E4C-3A6F-A25C-79F2D5F0721B none exfat rw,noauto
Don’t forget to alter the line according to your values (UUID and the filesystem in the third column).
