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The XFS filesystem is a high-performance journaling filesystem. It is ACL (POSIX) compliant for use with Linux.

XFS has a particularly strong reputation for reliability and led to the creation of the venerable xfstests Linux kernel test suite which now tests regressions in various filesystems.

Installation

Kernel

KERNEL Enable XFS support (CONFIG_XFS_FS:)

File systems  --->
   <*> XFS filesystem support

Optional:

KERNEL Enable optional XFS features

File systems  --->
   [*]   XFS Quota support
   [*]   XFS POSIX ACL support
   [*]   XFS Realtime subvolume support
   [ ]   XFS Verbose Warnings
   [ ]   XFS Debugging support

Emerge

The sys-fs/xfsprogs package is needed for XFS userspace utilities:

root #emerge --ask sys-fs/xfsprogs

Usage

Mount XFS filesystems with the mount command.

Make an XFS filesystem with mkfs.xfs from xfsprogs:

root #mkfs.xfs -L 'label'

The label is optional. Further tuning on creation might be interesting for use as a RAID, multi-terabyte drives, and doing the journaling for a HDD on a separate SSD.

XFS supports SSD discards in /etc/fstab.

Maintenance

Year 2038 timestamp support (bigtime)

Older partitions (created with <xfsprogs-5.15) will not have bigtime enabled by default. Mounting such partitions results in a warning like:

root #dmesg

...
[    4.036258] xfs filesystem being mounted at /home supports timestamps until 2038 (0x7fffffff)
...

To check the current version of xfsprogs, run mkfs.xfs -V. There's no need for this on up-to-date Gentoo systems, but it might be necessary if using install media from another distribution with older userland.

The bigtime code support was enabled by default in xfsprogs 5.15, so manual setting is not required in newer versions.

Beginning with kernel 5.10, XFS gained bigtime support to extend the maximum recorded date stamps from 2038 to 2486 for the V5 on-disk format.

To upgrade an older filesystem to bigtime, first cleanly unmount the file system. The upgrade will refuse to run if the unmount was not completely clean.

Then run:

root #xfs_admin -O bigtime=1 /dev/sda1

Replacing /dev/sda1 with the device path.

Note
XFS on the root mount will require an initramfs or other live environment with the necessary tools to perform an upgrade to the metadata.

Using Dracut initramfs to perform the upgrade

First, Dracut needs additional files included in the initramfs in order to perform the upgrade. This can be accomplished with either the --install option or inside a configuration file using the install_items option.

root #dracut --install "/usr/sbin/xfs_admin /usr/bin/expr" ...

Then, the kernel command line option can be modified to include rd.break=pre-mount to stop the initramfs just before it would mount the root filesystem. Ensure this is done temporarily and removed on subsequent reboots after upgrade.

Removal

To schedule removal at the next run:

root #emerge --ask --depclean --verbose sys-fs/xfsprogs

See also

• Deduplication — uses the clone mechanism of a copy-on-write or CoW capable filesystem, a feature that allows to share data of copied but identical files
• FAT — filesystem originally created for use with MS-DOS (and later pre-NT Microsoft Windows).
• Ext4 — an open source disk filesystem and most recent version of the extended series of filesystems.
• Btrfs — a copy-on-write (CoW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, self-healing properties, and easy administration.