Check disk health with SMART and NVMe evidence, not one green label
Device health combines self-assessment, error logs, media counters, temperature, and workload symptoms; a passed summary does not erase growing errors.
Explain a du vs df mismatch before deleting more files
Df reports filesystem block allocation while du walks visible names, so deleted-open files, mount overlays, snapshots, and reserved space can separate their totals.
Extend an LVM logical volume only after proving every storage layer
An LVM extension adds extents to a logical volume; the filesystem is a separate layer and may require its own online or offline growth step.
Find which Linux directory consumes inodes before cleanup
Inode exhaustion usually comes from many directory entries rather than large bytes, so file counts and ownership matter more than du size.
Find large files on Linux without crossing the wrong filesystem
Du summarizes reachable directory entries while find can select individual files; mount boundaries and permissions determine what either command can see.
Recover a read-only Linux filesystem without forcing unsafe writes
The kernel may remount a filesystem read-only to contain damage; recovery starts with preserving logs and identifying the device, not forcing remount-rw.
Use fstab nofail and automount without masking a missing disk
Nofail changes boot dependency behavior and x-systemd.automount defers the real mount until access; neither proves the storage is healthy or present.
Mount a Linux disk by UUID without creating a boot failure
Filesystem UUIDs provide a stable identity across device-name changes, but the UUID must still match the intended filesystem and mount options.
Resize an ext4 filesystem after verifying the device boundary
Ext4 can grow online when its containing block device is already larger, but partition, LVM, encryption, and filesystem sizes must be distinguished.
Grow an XFS filesystem from its mount point, not a guessed device
Xfs_growfs operates on a mounted XFS filesystem and grows within the already expanded underlying device; XFS does not support shrinking.