Linux System Installation & Configuration Flashcards

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

Answer: mount

Running 'mount' with no arguments prints all currently mounted filesystems, their mount points, types, and options.

What is the role of the initramfs (initial RAM filesystem) during Linux boot?

Answer: Provides a temporary root filesystem to load drivers and mount the real root

The initramfs is a compressed cpio archive that provides a minimal temporary root filesystem, allowing the kernel to load necessary drivers before mounting the real root.

Which LVM command extends a logical volume AND resizes its ext4 filesystem in one step?

Answer: lvextend -r -L +10G /dev/vg0/lv0

The -r flag with lvextend calls resize2fs automatically after extending the logical volume, handling both the LV and filesystem resize in one command.

Which file defines system-wide environment variables applied at login on most Linux distributions?

Answer: /etc/environment

/etc/environment is a PAM-read file that sets system-wide environment variables for all sessions regardless of shell.

What does the 'UUID=' syntax in /etc/fstab provide compared to using device names like /dev/sda1?

Answer: Stable identification that survives disk reordering

UUIDs uniquely identify filesystems regardless of which /dev/sdX name the kernel assigns, preventing boot failures when disk enumeration order changes.

Which command should be run after manually editing /etc/default/grub to apply the changes to the bootloader?

Answer: update-grub or grub2-mkconfig -o /boot/grub2/grub.cfg

/etc/default/grub is a template; you must run grub2-mkconfig (or update-grub on Debian-based systems) to regenerate the actual grub.cfg from it.

What is the minimum number of disks required to create a RAID 5 array?

Answer: 3

RAID 5 requires at least 3 disks: it stripes data with distributed parity across all disks, tolerating a single disk failure.