Bloomberg OS Interview: Linux VFS & Mounting

This question set focuses on Linux virtual filesystems (VFS) and practical mounting procedures that you’ll likely face in a Bloomberg systems or software-engineering interview.

You should be ready to explain the conceptual difference between the VFS layer and concrete on-disk filesystems, how the kernel routes file operations through inodes and dentries, and how user-space tools interact with that layer via mount/umount, /etc/fstab, and systemd. Expect to discuss common virtual filesystems such as procfs and tmpfs: when they are used, how they differ (e.g., tmpfs vs ramfs), and how they affect memory management and page cache.

Interview flow often starts with a high-level explanation (what is VFS, why it exists), moves to hands-on commands and configuration (mount options, persistence via /etc/fstab or systemd .mount units), and finishes with troubleshooting scenarios (mount failures, permission denied errors, SELinux contexts, and kernel module loading). You may be asked to interpret output from dmesg, mount, lsmod, /proc/filesystems, and journalctl.

Skill signals: demonstrate understanding of kernel/user-space boundaries, filesystem types and tradeoffs, memory implications of tmpfs, common Linux commands and config files, and systematic debugging approaches. Practical examples and clear command usage will strengthen your answers.