Which sequence creates an XFS filesystem on /dev/sdXn and mounts it with noatime, updating /etc/fstab?

• A. mkfs.xfs /dev/sdXn; echo '/dev/sdXn /mnt/xfs xfs defaults,noatime 0 0' >> /etc/fstab; mount -a
• B. mkfs.xfs /dev/sdXn; mount -a
• C. mkfs.ext4 /dev/sdXn; echo '/dev/sdXn /mnt/xfs xfs defaults,noatime 0 0' >> /etc/fstab; mount -a
• D. mkfs.xfs /dev/sdXn; echo '/dev/xsDxn /mnt/xfs xfs defaults, relatime 0 0' >> /etc/fstab

Answer: (A)

Formatting a partition as XFS and configuring fstab to mount it with noatime is what this is testing. You create the XFS filesystem with mkfs.xfs on the device (for example /dev/sdXn). Then ensure a mount point exists, such as /mnt/xfs. Add an fstab entry using the device, the mount point, and the filesystem type xfs, with options including noatime (commonly defaults,noatime). The dump and fsck fields are typically 0 0 for non-root filesystems. Finally, run mount -a to apply all entries in /etc/fstab. This sequence ensures the filesystem is created as XFS, the noatime behavior is in effect, and the system can mount it via fstab. The other options fail because they either format with a different filesystem (ext4), omit updating fstab so mount -a has nothing to mount, or reference a misspelled device or use a conflicting option (such as relatime) that does not meet the noatime requirement.