RHCSA Filesystem and Mount Configuration Flashcards

Which command displays the UUID of all block devices on a RHEL system?

Answer: blkid

blkid queries and displays block device attributes including UUID, filesystem type, and label.

What entry in /etc/fstab would mount a filesystem with UUID 1234-ABCD at /data with read-only access?

Answer: UUID=1234-ABCD /data ext4 ro 0 2

The fstab entry uses UUID= as the device field, followed by mountpoint, filesystem type, and options including 'ro' for read-only.

Which command checks and repairs an ext4 filesystem on /dev/sdb1 without interactive prompts?

Answer: e2fsck -y /dev/sdb1

e2fsck -y automatically answers 'yes' to all repair questions, enabling non-interactive filesystem repair.

A system fails to boot because of an incorrect /etc/fstab entry. Which kernel parameter allows you to boot into a rescue shell to fix it?

Answer: rd.break

rd.break interrupts the boot process before the root filesystem is mounted, providing a rescue shell to fix fstab issues.

What does the last field (pass) in an /etc/fstab entry control?

Answer: The order in which fsck checks filesystems at boot

The pass field controls the order in which fsck checks filesystems at boot; 0 means skip, 1 is for root, 2 for others.

Which command shows disk usage summary for each directory under /var, sorted by size?

Answer: du -sh /var/* | sort -h

du -sh provides a summary of disk usage for each item, and sort -h sorts human-readable sizes correctly.

What is the purpose of the 'noatime' mount option in /etc/fstab?

Answer: Prevents updating the access time on files when they are read

noatime improves performance by not updating the access time (atime) metadata every time a file is read.