Disk Slices (System Administration Guide: Devices and File Systems)

System Administration Guide: Devices and File Systems

Disk Slices

The following table describes the slices that might be found on a system that runs the Solaris OS.

On x86 systems:

Disks are divided into fdisk partitions. An fdisk partition is a section of the disk that is reserved for a particular operating system, such as the Solaris OS.
The Solaris OS places ten slices, numbered 0-9, on a Solaris fdisk partition.

Table 10–2 Customary Disk Slices


Slice	File System	Usually Found on Client or Server Systems?	Comments
0	root (`/`)	Both	Holds files and directories that make up the OS. EFI – You cannot boot from a disk with an EFI label.
1	swap	Both	Provides virtual memory, or swap space.
2	—	Both	VTOC – Refers to the entire disk, by convention. The size of this slice should not be changed. EFI – Optional slice to be defined based on your site's needs.
3	`/export`, for example	Both	Optional slice that can be defined based on your site's needs. Can be used on a server to hold alternative versions of operating systems that are required by client systems.
4		Both	Optional slice to be defined based on your site's needs.
5	`/opt`, for example	Both	Optional slice to be defined based on your site's needs. Can be used to hold application software added to a system. If a slice is not allocated for the `/opt` file system during installation, the `/opt` directory is put in slice 0.
6	`/usr`	Both	Holds OS commands (also known as executables). This slice also holds documentation, system programs (`init` and `syslogd`, for example), and library routines.
7	`/home` or `/export/home`	Both	Holds files that are created by users.
8	N/A	N/A	VTOC – Contains GRUB boot information. EFI – A reserved slice created by default. This area is similar to the VTOC's alternate cylinders. Do not modify or delete this slice.
9 (x86 only)	—	Both	EFI – Not applicable. VTOC – Provides an area that is reserved for alternate disk blocks. Slice 9 is known as the alternate sector slice.

Note –

On a disk with a VTOC label, do not modify slice or use slice 2 to store a file system. Products, such as Solaris Volume Manager, Solaris Live Upgrade, and installgrub, do not work correctly if slice 2 is modified in any way.