CompTIA Linux+ (XK0-006)System ManagementMedium
A pilot deployment adds a new external drive, /dev/sdc1, to a server. The technician wants the drive to always mount reliably at /data even if the device name changes after a reboot (e.g., becomes /dev/sdd1). What should the technician do first, and what should the /etc/fstab entry reference?
- ARun 'blkid /dev/sdc1' to find its UUID, then reference UUID= in /etc/fstab
- BReference /dev/sdc1 directly in /etc/fstab since device names never change
- CReference the partition by its /proc/partitions entry number
- DAdd the mount command to /etc/rc.local using /dev/sdc1
Show answer & explanationAnswer & explanation
Correct answer: A. Run 'blkid /dev/sdc1' to find its UUID, then reference UUID= in /etc/fstab
Device names like /dev/sdc1 can shift between boots due to detection order changes, especially with hot-swappable or USB drives. Using 'blkid' to retrieve the partition's UUID and referencing UUID= in /etc/fstab ensures the correct device is mounted regardless of its assigned name.
Why the other options are wrong
- B. Device names can change between boots, making this unreliable.
- C. /proc/partitions is a dynamic virtual file and not a valid fstab identifier.
- D. rc.local is a legacy, less reliable approach and doesn't solve the naming issue.
UUID-Based Mounting
Using the unique UUID of a filesystem in /etc/fstab ensures a device mounts consistently regardless of its detected device name.
- Retrieve UUID with 'blkid' or 'lsblk -f'
- Prevents mount failures from device renumbering
- Format in fstab: UUID=xxxx-xxxx /mountpoint ext4 defaults 0 2
Memory trick: UUID = a device's 'fingerprint' that never changes, unlike its nickname