Troubleshooting
Which journalctl command shows kernel messages from the current boot only?
- Ajournalctl -k -bCorrect
- Bjournalctl --disk-usage
- Cjournalctl -f
- Djournalctl --vacuum-time=1d
Why: 'journalctl -k' limits output to kernel messages (like dmesg) and '-b' limits it to the current boot, so '-k -b' shows this boot's kernel log. '-f' follows new entries, and '--vacuum-time' deletes old journal data rather than displaying it.
System Management
Which directory in the Filesystem Hierarchy Standard is intended to hold variable data such as logs, spool files, and caches?
- A/usr
- B/opt
- C/etc
- D/varCorrect
Why: /var stores variable data that changes during normal operation, including /var/log, /var/spool, and /var/cache. /etc holds system configuration, /usr holds read-only user programs and libraries, and /opt holds optional add-on software packages.