Which command reveals inode depletion?

• A. df -i reveals inode depletion.
• B. df -h reveals inode depletion.
• C. du -a reveals inode depletion.
• D. lsof reveals inode depletion.

Answer: (A)

Inodes are the metadata units that represent files on a filesystem, and running out of inodes means you can’t create new files even if there’s free disk space. To detect this, you need to check the inode counts per filesystem. The command that reports inode usage is the one that uses the -i option with df; it shows how many inodes are used and how many are free (IUsed, IFree, IUse%). If IFree is zero or very low and IUse% is high, you’re experiencing inode depletion.

The other commands don’t reveal inode status in the same way: df -h shows disk space in human-readable units but not inode counts; du -a reports disk usage by files and directories but not inodes; lsof lists open files but doesn’t indicate inode availability. So df -i is the direct tool to detect inode depletion.