On Linux systems, which command is used to create a new file system on a partition or block device before it can be mounted?

Introduction / Context:
Before a partition or block device can be used for storing files, it must be formatted with a file system. Linux provides a specific command for this purpose, which abstracts details of different file system types.

Given Data / Assumptions:

• We have a new or unformatted partition or block device.
• We want to create a usable file system on it.
• Linux standard utilities are installed.

Concept / Approach:

The mkfs command ('make file system') initializes a partition with a chosen file system (ext4, xfs, vfat, etc.). Variants like mkfs.ext4 or mkfs.xfs provide specific implementations.

Step-by-Step Solution:

Verification / Alternative check:

Check with file -s /dev/sdb1 or blkid. Mount and verify with df -h.

Why Other Options Are Wrong:

• fdisk: partitions disks, does not format.
• fsck: checks and repairs file systems.
• mount: attaches a filesystem to a directory tree, does not create one.
• None: incorrect since mkfs is correct.

Common Pitfalls:

• Confusing partitioning with formatting.
• Accidentally formatting the wrong device (always double-check identifiers).

Final Answer:

mkfs.