You run `ln /data/report.txt /data/backup.txt` and then `rm /data/report.txt`. What is the state of the data afterwards?
LPIC-1 Exam 101-500, objective 104. Devices, Linux filesystems, filesystem hierarchy standard hard
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The options
Not correct The data is gone, because rm always frees the file's blocks immediately.
Wrong. rm calls unlink(), which removes one name. Blocks are released only when the last name and the last open descriptor are gone.
Not correct /data/backup.txt is now a dangling link and reading it fails with 'No such file or directory'.
Wrong — that is symbolic link behaviour. A symlink stores a path, so deleting the target breaks it. A hard link stores nothing but a name pointing at an inode.
Correct The data is fully intact and reachable through /data/backup.txt; the inode's link count simply dropped from 2 to 1.
Correct. Both names always pointed at the same inode. rm removes a directory entry and decrements the link count; the blocks are freed only when the count reaches 0 and no process holds the file open.
Not correct /data/backup.txt still exists but is now an empty file of zero bytes.
Wrong. Nothing truncates the inode. Its size, contents, permissions and timestamps are unchanged; only the link count in the inode changed.
Why
A hard link is an additional directory entry pointing at the same inode, so all names are equally 'the file' — there is no original. `ls -l` shows the link count in the second column, and `ls -i` shows that the names share one inode number. Hard links cannot span filesystems (inode numbers are only unique within one) and ordinary users cannot create them to directories.
Where this comes from
- Cited
- LPI exam objective 104.6
- What it says
- Create hard links and understand how they differ from symbolic links.
Practise this
Reading one question is not practice. The trainer will draw a set from objective 104 and space the ones you get wrong.