LCA File Systems & Storage Management 2 — Questions and Answers
Question 1: Which command displays the UUID of a block device?
- blkid (Correct answer)
- fdisk -l
- lsblk -f
- df -h
Correct answer: blkid
blkid queries block device attributes including UUID, filesystem type, and label.
Question 2: What does the 'noatime' mount option do?
- Disables access time updates on reads (Correct answer)
- Prevents file modification timestamps from updating
- Mounts the filesystem read-only
- Disables creation time tracking
Correct answer: Disables access time updates on reads
noatime prevents updating the atime (access time) inode field on every read, reducing disk writes.
Question 3: Which LVM command extends a logical volume AND resizes its ext4 filesystem in one step?
- lvextend -r -L +10G /dev/vg0/lv0 (Correct answer)
- lvresize /dev/vg0/lv0 +10G
- vgextend vg0 +10G
- resize2fs /dev/vg0/lv0
Correct answer: lvextend -r -L +10G /dev/vg0/lv0
lvextend -r (--resizefs) calls resize2fs automatically after extending the LV.
Question 4: In /etc/fstab, what does the fifth field (fs_freq) control?
- Whether dump backs up the filesystem (Correct answer)
- The fsck check order at boot
- Mount frequency in seconds
- The number of reserved blocks
Correct answer: Whether dump backs up the filesystem
The fifth field is used by the dump utility to determine which filesystems need to be backed up.
Question 5: Which RAID level provides striping with double distributed parity, tolerating up to two simultaneous disk failures?
- RAID 6 (Correct answer)
- RAID 5
- RAID 10
- RAID 50
Correct answer: RAID 6
RAID 6 uses two independent parity blocks distributed across all drives, surviving two disk failures.
Question 6: What is the purpose of the 'tune2fs -c 20 /dev/sdb1' command?
- Set maximum mount count before fsck is forced to 20 (Correct answer)
- Set the check interval to 20 days
- Reserve 20 blocks for root
- Create 20 extra inodes
Correct answer: Set maximum mount count before fsck is forced to 20
tune2fs -c sets the maximum number of mounts before an automatic filesystem check is triggered.
Question 7: Which filesystem type is specifically designed for flash/SSD storage without a journal to minimize write amplification?
- F2FS (Correct answer)
- ext4
- XFS
- Btrfs
Correct answer: F2FS
F2FS (Flash-Friendly File System) is designed by Samsung for NAND flash storage, optimizing write patterns for SSDs.
LCA File Systems & Storage Management 2
Which command displays the UUID of a block device?