On an ext4 filesystem at /dev/sda1 you want an automatic check to be forced after every 30 mounts. Which command sets that?
LPIC-1 Exam 101-500, objective 104. Devices, Linux filesystems, filesystem hierarchy standard hard
Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.
Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Not correct tune2fs -i 30 /dev/sda1
Wrong. -i sets the time interval between checks; a bare number means days, so this means 30 days, not 30 mounts. Suffixes d, w and m select days, weeks and months.
Correct tune2fs -c 30 /dev/sda1
Correct. -c sets the maximum mount count between checks. -c 0 or -c -1 disables mount-count-based checking, which many distributions do by default.
Not correct tune2fs -L 30 /dev/sda1
Wrong. -L sets the filesystem label. This would name the filesystem "30", which is legal and useless here.
Not correct dumpe2fs -h /dev/sda1
Wrong. dumpe2fs is read-only; -h prints just the superblock, including the current mount count and maximum mount count. It reports the setting, it does not change it.
Why
tune2fs adjusts ext2/3/4 superblock parameters on an existing filesystem: -c mount count, -i time interval, -L label, -U UUID, -m reserved-blocks percentage. dumpe2fs is its read-only counterpart for inspecting the same values.
Where this comes from
- Cited
- LPI exam objective 104.2
- What it says
- Tune ext filesystem parameters with tune2fs and inspect them with dumpe2fs.
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 104 and space the ones you get wrong.
More questions on this objective
- A new disk /dev/sdb has no partition table at all. Which command writes an empty GPT partition table onto it without dropping you into an interactive editor? machine-checked
- You need the partition /dev/sdc1 on a USB stick to carry a FAT32 filesystem so that Windows machines can read and write it. Which command creates it? machine-checked
- You have just run `mkswap /dev/sdb2`. Which command makes the kernel start using that swap area immediately, without a reboot? machine-checked
- Why is it dangerous to run e2fsck against an ext4 filesystem that is currently mounted read-write? machine-checked
- `df -h /var` reports the filesystem 100% full, but `du -sh /var` accounts for only about half that space. Nothing is hidden under a mount point. What is the most likely explanation? machine-checked
- An XFS filesystem on /dev/sdb1 was damaged by a power loss and must be checked and repaired. Which command is the right tool, and what state must the filesystem be in? machine-checked
All questions on Devices, Linux filesystems, filesystem hierarchy standard