Ext4

ext4 is an open source disk filesystem and the most recent version of the ext series.

Kernel
Activate the following kernel options for ext4 support:

USE flags
The package contains the utilities to work with the filesystem. In Gentoo Linux is part of the system set and should be already installed on the system.

Emerge
After setting the USE flag update the system so the changes take effect:

Large drive support
When the system has large disks (2 TB or greater) and a 32-bit (x86) kernel is being used, the following option must be enabled:

Creation
To create an ext4 filesystem on the partition:

Please replace with the actual partition to format.

By default, 5% of available disk space is reserved for the root user. This is usually a good thing for the partition where the directory is mounted, but it may be not desirable on other partitions. To lose reserve disk space for the root user use mkfs.ext4's  option:

Mount
Filesystems can be mounted in several ways:


 * mount - Manual mount.
 * fstab - Automatic mount at boot time.
 * removable media - Automatic mount at demand.
 * AutoFS - Automatic mount on access.

External resources

 * ext4 wiki