File systems & mounts.
A partition is just bytes until you format it with a filesystem and mount it somewhere. Watch a block device become an XFS filesystem, get mounted, and survive a reboot via /etc/fstab — then learn the options that govern its behavior.
Linux filesystems and mounts animated tutorial. mkfs.xfs and mkfs.ext4, the mount command, mount options, /etc/fstab format and UUIDs, fsck and tune2fs, xfs_growfs and resize2fs. RHCSA EX200 ready.From a bare partition to a mounted, persistent filesystem — six layers, all with their own commands.
- ·The partitions lesson (lsblk, blkid)
- ·Comfortable as root
- ·Know what a journaling filesystem is, vaguely
Format a partition with mkfs, mount it, persist it in /etc/fstab using UUID, pick the right mount options, and grow / check it.
pace: 9 minutes
/dev/sdb1(none)(unmounted)(no entry)Pick a filesystem — XFS or ext4
Two RHCSA defaults: XFS (RHEL's default since 7) — fast, scales to huge volumes, grows online but CANNOT shrink. ext4 — slightly older, slower at scale, supports BOTH grow and shrink (offline shrink). Pick XFS unless you specifically need to shrink. Both journal, both are stable.
$lsblk -f /dev/sdb1$blkid /dev/sdb1The chain: block device → filesystem → mount → fstab. Skip the last step and your work vanishes at reboot. ALWAYS run `mount -a` after editing fstab — if you don't, the next reboot might drop into emergency mode and the only way out is rescue media.
$mkfs.xfs / mkfs.ext4 DEV$mkfs.xfs -L LABEL DEV$mount DEV MOUNTPOINT$umount MOUNTPOINT$mount -a$mount -o remount,ro DIR$findmnt / findmnt --verify$lsof DIR / fuser -mv DIR$blkid DEV$/etc/fstab$xfs_growfs MP$resize2fs DEV$xfs_repair DEV (unmounted)$fsck.ext4 -y DEV$tune2fs -l DEV$df -hT / du -sh DIRYou added a new line to /etc/fstab and want to verify it works WITHOUT rebooting.
You need to SHRINK a filesystem. Which filesystem can you use?
`umount /data` returns 'target is busy'. How do you find the culprit?
Why reference partitions by UUID in /etc/fstab?
These aren't graded — they're just for active recall, which is what actually makes the lesson stick.
LVM stacking
Put LVM between the partition and the filesystem and growing space online becomes one command. See the whole stack: disks → PVs → VG → LVs → FS.
keep going — these pair well with what you just learned.
SELinux contexts
Why Apache can't read your file. Watch the policy engine decide — and learn the workflow for fixing denials. RHCSA-ready.
Linux boot process
From power button to login prompt. Every stage in the chain — UEFI, GRUB, kernel, initramfs, systemd — with the rescue moves that save you. RHCSA-ready.
LVM stacking
Layer-by-layer build of an LVM stack: disks → PVs → VG → LVs → filesystem. Then extend live and snapshot. RHCSA-ready.