Hands-on Lab·Red Hat Certified System Administrator
XFS, ext4 and VFAT Filesystems
Three filesystems, three `mkfs` commands, and one asymmetry that matters: **XFS cannot be shrunk**. ext4 is shrunk here to prove the contrast, and VFAT is shown silently ignoring a `chmod` - because it has no concept of Unix permissions at all.
File Systems Guide 37 of 67 Intermediate
- OSRHEL 10.0 (Coughlan)
- Kernel6.12.0-55.9.1.el10_0
- dnf4.20.0
- Flatpak1.16.0
- TimeAbout 16 min
- Reviewed23 August 2026
Written against the versions above. XFS is RHEL's default for `/` and has been since RHEL 7. It can grow while mounted and can never shrink - there is no `xfs_shrink` and no shrink option to `xfs_growfs`. That single fact should decide how generously you size a volume.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| RHCSA-A01 | 192.168.0.31 | RHEL 10.0 (Coughlan) | Practice node (graded) - spare /dev/sda | 2 Core | 4 GB | 50 GB + 15 GB |
Before you start
- A volume group with about 1.2 GB free -
guide 33builds one. - The session creates and removes three logical volumes and three mount points.
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Three volumes to format
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XFS
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ext4, and the space it holds back
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VFAT has no permissions
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The difference that decides your sizing