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ext3 (third extended filesystem) is an open source disk filesystem created for Linux, its driver being discontinued since linux 4.3.



Activate the following kernel options for ext3 support:

KERNEL Enabling ext3 support
File systems  --->
   <*> Ext3 journalling file system support

Support for optional ext3 features:

KERNEL Enabling ext3 features
File systems  --->
   [*]   Default to 'data=ordered' in ext3 
   [*]   Ext3 extended attributes
   [*]     Ext3 POSIX Access Control Lists
   [*]     Ext3 Security Labels
Optional ext3 support definitions
Option Description
Default to 'data=ordered' in ext3
Ext3 extended attributes Extended attributes are name:value pairs associated with inodes by the kernel or by users. See http://acl.bestbits.at/
Ext3 POSIX Access Control Lists Posix Access Control Lists (ACLs) support permissions for users and groups beyond the owner/group/world scheme. See http://acl.bestbits.at/
Ext3 Security Labels Enables an extended attribute handler for file security.

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:

KERNEL Enabling large drives for x86 kernels
-*- Enable the block layer  --->
    [*]   Support for large (2TB+) block devices and files

USE flags

The sys-fs/e2fsprogs package contains the utilities to work with the filesystem. In Gentoo Linux sys-fs/e2fsprogs is part of the system set and should be already installed on the system.

USE flags for sys-fs/e2fsprogs Standard EXT2/EXT3/EXT4 filesystem utilities

fuse Build fuse2fs, a FUSE file system client for ext2/ext3/ext4 file systems local
static-libs Build static versions of dynamic libraries as well global


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

root #emerge --ask --changed-use --deep @world



The mkfs.ext3 command irreversibly destroys any content of the partition it is told to format. Be sure to select the right partition!

To create an ext3 filesystem on the /dev/sda1 partition:

root #mkfs.ext3 /dev/sda1

Please replace /dev/sda1 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.ext3's -m 0 option:

root #mkfs.ext3 -m 0 /dev/sda1

External resources