Mac OSX storage have 4 different concepts: disk, formatting, partition and volume. Disk are the physical devices where data are kept.
Disk may be divided on several areas or partitions, every partition may contain own and be data partition as well. OSX may support up to 16 partitions per disk. OSX supports 2 main partition schemes: Apple Partition Map (APM) and GUID Partition Table (GPT) plus additional; partition scheme Master Boot Record (MBR).
When partition is created the volumes can be created as well inside this partition. The volume content include files and folders. What we are seeing in the Finder or terminal is actually volumes not a partition:
# ls -l /Volumes/ total 0 drwxr-xr-x 8 sshtest staff 340 Nov 23 2018 CLion drwxr-xr-x@ 7 _unknown _unknown 238 Aug 30 2018 Firefox lrwxr-xr-x 1 root wheel 1 Jun 14 10:18 Macintosh HD -> / drwxr-xr-x@ 4 root wheel 128 Apr 16 2018 Recovery drwxr-xr-x 6 root wheel 272 May 4 01:55 RecoveryHDMeta drwxr-xr-x@ 11 _unknown _unknown 442 Sep 10 2018 Skype |
Information about physical drive may be retrieved using system_profiler command with specific argument type for particular physical storage, for example:
# system_profiler SPSerialATADataType SATA/SATA Express: Generic AHCI Controller: Vendor: Generic VMware Virtual SATA Hard Drive: Capacity: 64.42 GB (64,424,509,440 bytes) |
or using diskutil, additionally diskutil gives partition and file system information. The example below shows Apple_HFS file system, which mean Apple Hierarchy File System:
# diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE 0: GUID_partition_scheme *64.4 GB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_HFS MacOS 3.6 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 ….. /dev/disk2 (disk image): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme +47.2 MB disk2 1: Apple_HFS MyApp Installer 47.2 MB disk2s1 /dev/disk3 (disk image): |