LCA Backup & Disaster Recovery 4 — Questions and Answers
Question 1: Which rsync option enables compression of data during transfer to reduce bandwidth usage?
- -z (Correct answer)
- -c
- -e
- -n
Correct answer: -z
rsync -z compresses file data during the transfer, which reduces bandwidth at the cost of extra CPU usage on both endpoints.
Question 2: When using 'rsync --delete', what happens to files at the destination that no longer exist at the source?
- They are deleted from the destination (Correct answer)
- They are moved to a trash folder
- They are archived before deletion
- They are ignored and left in place
Correct answer: They are deleted from the destination
rsync --delete removes files from the destination that are no longer present at the source, keeping the destination a true mirror.
Question 3: Which command would you use to restore a specific file 'etc/passwd' from a tar archive 'backup.tar.gz'?
- tar -xzf backup.tar.gz etc/passwd (Correct answer)
- tar -czf backup.tar.gz etc/passwd
- tar -tzf backup.tar.gz etc/passwd
- tar -rzf backup.tar.gz etc/passwd
Correct answer: tar -xzf backup.tar.gz etc/passwd
tar -xzf extracts (-x) from a gzip-compressed (-z) archive file (-f), and specifying 'etc/passwd' restores only that file.
Question 4: A disaster recovery plan calls for a 'warm standby' site. What best describes this?
- A site with hardware and software pre-configured but not actively processing live traffic (Correct answer)
- A site that mirrors production in real time and can take over instantly
- A site with empty racks and no installed equipment
- A cloud-based backup with no physical hardware
Correct answer: A site with hardware and software pre-configured but not actively processing live traffic
A warm standby site has hardware and software ready but runs on recent (not real-time) data and requires some activation time before it can serve production traffic.
Question 5: What is the purpose of the 'mt' command in Linux backup operations?
- Control magnetic tape drive operations such as rewind, eject, and seek (Correct answer)
- Mount a backup tape filesystem
- Format a new tape for use
- List files stored on a tape archive
Correct answer: Control magnetic tape drive operations such as rewind, eject, and seek
The mt (magnetic tape) command sends control operations to a tape drive, such as rewinding, forwarding, ejecting, or seeking to a specific position.
Question 6: Which /proc file provides information useful for identifying mounted filesystems that should be included in a backup plan?
- /proc/mounts (Correct answer)
- /proc/partitions
- /proc/filesystems
- /proc/diskstats
Correct answer: /proc/mounts
/proc/mounts lists all currently mounted filesystems including their mount points, device, and options, helping identify what must be backed up.
Question 7: Which option in crontab syntax schedules a backup job to run at 2:30 AM every Sunday?
- 30 2 * * 0 (Correct answer)
- 2 30 * * 0
- 30 2 * * 7
- 0 2 30 * *
Correct answer: 30 2 * * 0
Crontab fields are minute hour day month weekday; '30 2 * * 0' means minute 30, hour 2, any day/month, weekday 0 (Sunday).
LCA Backup & Disaster Recovery 4
Which rsync option enables compression of data during transfer to reduce bandwidth usage?