Mastering XFS: Features, Installation, and Migration on Linux

XFS Filesystem Overview

XFS is a high‑performance, scalable, and robust journaling file system originally developed by SGI and later ported to Linux. The latest usable version (1.2) works well with the 2.4 kernel.

Key Features

Data integrity : Journaling ensures rapid recovery after unexpected crashes.

Performance : Optimized algorithms keep logging overhead low; XFS shows superior speed compared with JFS, Ext3, and ReiserFS.

Scalability : Fully 64‑bit, supporting up to 9 exabytes per file and 18 exabytes per file system, with fast B+‑tree searches.

Bandwidth : Near‑raw device I/O performance, up to 7 GB/s overall and 4 GB/s for single‑file reads/writes.

Using XFS on Linux

Downloading and patching the kernel

# cd /usr/src/linux
# patch -p1 < /path/to/xfs-1.1-2.4.18-all.patch

After patching, enable XFS support in the kernel configuration and compile:

# make menuconfig
# make bzImage
# make modules
# make modules_install
# make install

Creating an XFS filesystem

Install the XFS utilities (xfsprogs) and format a partition:

# tar -xvf xfsprogs-2.0.3.src.tar.gz
# cd xfsprogs-2.0.3src
# ./configure
# make
# make install
# /sbin/mkfs.xfs /dev/sda6

If the partition was previously formatted with another file system, force formatting with -f:

# /sbin/mkfs.xfs -f /dev/sda6

Mounting and auto‑loading

# mount -t xfs /dev/sda6 /xfs

Add an entry to /etc/fstab so the XFS partition mounts automatically at boot.

Filesystem Migration

Before converting other partitions to XFS, back up all data. To achieve a pure XFS system, create an intermediate ext2 partition, copy the entire root file system to it, update /etc/fstab and bootloader configuration (e.g., /etc/lilo.conf), then reboot. After confirming the new root works, format the original root partition as XFS and repeat the copy‑back process.