Gentoo Linux AMD64 Handbook

Preparing the Disks
ext3 is the journaled version of the ext2 filesystem, providing metadata journaling for fast recovery
in addition to other enhanced journaling modes like full data and ordered data journaling. It uses an
HTree index that enables high performance in almost all situations. In short, ext3 is a very good and
reliable filesystem. If you intend to install Gentoo on a very small disk (less than 4GB), then you'll
need to tell ext3 to reserve enough inodes when you create the filesystem. The mke2fs application
uses the "bytes-per-inode" setting to calculate how many inodes a file system should have. By running
mke2fs -j -T small /dev/ the number of inodes will generally quadruple for a given file
system as its "bytes-per-inode" reduces from one every 16kB to one every 4kB. You can tune this
even further by using mke2fs -j -i /dev/.
ext4 is a filesystem created as a fork of ext3 bringing new features, performance improvements and
removal of size limits with moderate changes to the on-disk format. It can span volumes up to 1 EB and
with maximum file size of 16 TB. Instead of the classic ext2/3 bitmap block allocation ext4 uses extents
[http://en.wikipedia.org/wiki/Extent_%28file_systems%29], which improve large file performance
and reduce fragmentation. Ext4 also provides more sophisticated block allocation algorithms (delayed
allocation and multiblock allocation) giving the filesystem driver more ways to optimise the layout
of data on the disk. The ext4 filesystem is a compromise between production-grade code stability and
the desire to introduce extensions to an almost decade old filesystem. Ext4 is the recommended allpurpose
all-platform filesystem.
JFS is IBM's high-performance journaling filesystem. JFS is a light, fast and reliable B+tree-based
filesystem with good performance in various conditions.
ReiserFS is a B+tree-based journaled filesystem that has good overall performance, especially when
dealing with many tiny files at the cost of more CPU cycles. ReiserFS appears to be less maintained
than other filesystems.
XFS is a filesystem with metadata journaling which comes with a robust feature-set and is optimized
for scalability. XFS seems to be less forgiving to various hardware problems.
Applying a Filesystem to a Partition
To create a filesystem on a partition or volume, there are tools available for each possible filesystem:
Filesystem
ext2
ext3
ext4
reiserfs
xfs
jfs
Creation Command
mkfs.ext2
mkfs.ext3
mkfs.ext4
mkreiserfs
mkfs.xfs
mkfs.jfs
For instance, to have the boot partition (/dev/sda1 in our example) in ext2 and the root partition
(/dev/sda3 in our example) in ext4 (as in our example), you would use:
Example 4.17. Applying a filesystem on a partition
# mkfs.ext2 /dev/sda1
# mkfs.ext4 /dev/sda3
Now create the filesystems on your newly created partitions (or logical volumes).
Activating the Swap Partition
mkswap is the command that is used to initialize swap partitions:
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