CompTIA Linux+ (XK0-006)TroubleshootingMedium

An administrator adds a new physical volume to a volume group and extends the logical volume for /home with `lvextend -L +10G /dev/vgdata/lvhome`. The /home filesystem uses XFS. After running the command, `df -h` still shows the old, smaller size for /home. What step was missed?

  1. ARun `resize2fs /dev/vgdata/lvhome` to grow the filesystem
  2. BRun `vgextend` again to add the same physical volume a second time
  3. CReboot the server so the kernel re-reads the partition table
  4. DRun `xfs_growfs /home` to grow the XFS filesystem to match the new LV size
Show answer & explanation

Correct answer: D. Run `xfs_growfs /home` to grow the XFS filesystem to match the new LV size

lvextend only grows the logical volume; the filesystem itself must be separately resized to use the new space. Since /home is XFS, the correct tool is xfs_growfs (resize2fs only works on ext2/3/4 filesystems), and it can be run online without unmounting.

Why the other options are wrong

  • A. resize2fs only works on ext2/3/4 filesystems, not XFS.
  • B. Running vgextend again on the same PV would fail or have no effect; it doesn't resize the filesystem.
  • C. A reboot is unnecessary for LVM/filesystem resizing and won't grow the filesystem.

LVM + Filesystem Resize

Extending an LVM logical volume with lvextend does not automatically grow the filesystem; you must also resize the filesystem using the correct tool for its type.

  • ext2/3/4: use resize2fs
  • XFS: use xfs_growfs (can only grow, never shrink)
  • Combine both steps with lvextend -r to resize automatically

Memory trick: Bigger box (LV) still needs bigger shelves (filesystem) — match the tool to the filesystem type

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