RHCSA Filesystem and Mount Configuration Flashcards

Which command adds a label 'BACKUP' to an ext4 filesystem on /dev/sdb1?

Answer: tune2fs -L BACKUP /dev/sdb1

tune2fs -L sets or changes the filesystem label on an existing ext4 filesystem without reformatting.

A mount point /mnt/data has the 'nofail' option in /etc/fstab. What happens if the device is absent at boot?

Answer: The system boots normally and skips mounting that entry

nofail tells systemd not to fail the boot if this mount cannot be completed, allowing the system to continue booting.

Which command mounts all filesystems listed in /etc/fstab that are not currently mounted?

Answer: mount -a

mount -a reads /etc/fstab and attempts to mount all filesystems that have the 'auto' option and are not already mounted.

What does the fifth field (dump) in an /etc/fstab entry control?

Answer: Whether the dump backup utility backs up the filesystem

The dump field (0 or 1) tells the legacy dump utility whether to include this filesystem in backups; 0 means skip.

Which command shows all currently mounted filesystems along with their mount options?

Answer: findmnt

findmnt displays all mounted filesystems in a tree format including mount options, source, and type.

An NFS share nfs-server:/exports/data needs to mount at /mnt/nfs. Which fstab entry is correct?

Answer: nfs-server:/exports/data /mnt/nfs nfs defaults 0 0

NFS fstab entries use server:/path as the device, the local mountpoint, 'nfs' as the type, and 0 0 for dump and pass fields.

Which command unmounts /mnt/usb and ensures all pending writes are flushed before removal?

Answer: umount /mnt/usb

umount itself flushes buffers and ensures data is written before unmounting; running sync beforehand is redundant but harmless.