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Filesystems: Making Partitions Usable

Filesystems organize data on partitions. Without a filesystem, you can't use the partition.

Here's the thing: You'll mostly use ext4. It's the default. It works. Learn the others when you need them.

Common Filesystems​

ext4: The Standard​

What: Default on most Linux systems.

Characteristics:

  • Journaling (crash recovery)
  • Good performance
  • Reliable
  • 16TB max file size

My take: Use ext4. It's the default. It works. Don't overthink it.

xfs: High Performance​

What: Better for large files and high I/O.

Characteristics:

  • Excellent for large files
  • High I/O performance
  • 8EB max file size

When to use: Databases. Large files. High performance needs.

My take: Use xfs when you need performance. Otherwise, ext4 is fine.

btrfs: Advanced Features​

What: Modern filesystem with advanced features.

Characteristics:

  • Snapshots
  • Compression
  • Copy-on-write
  • RAID support

When to use: When you need snapshots or advanced features.

My take: btrfs is advanced. Use it when you need its features. Otherwise, ext4.

Creating Filesystems​

mkfs: Make Filesystem​

sudo mkfs.ext4 /dev/sda1          # Create ext4
sudo mkfs.xfs /dev/sda1           # Create xfs
sudo mkfs.btrfs /dev/sda1         # Create btrfs

My take: mkfs creates filesystems. Simple. Works.

Format with Label​

sudo mkfs.ext4 -L "data" /dev/sda1

My take: Labels help identify filesystems. Use them.

Checking Filesystems​

sudo fsck /dev/sda1               # Check filesystem
sudo fsck.ext4 /dev/sda1          # Check ext4

My take: fsck checks filesystems. Run it if something seems wrong.

Common Patterns​

Format New Partition​

# 1. Create partition (fdisk)
sudo fdisk /dev/sda

# 2. Format
sudo mkfs.ext4 /dev/sda1

# 3. Mount
sudo mount /dev/sda1 /mnt/data

Common Mistakes (I've Made These)​

  1. Formatting wrong device: Double-check device name. Formatting destroys data.

  2. Not mounting after format: Formatting doesn't mount. Mount manually.

  3. Wrong filesystem type: Use ext4 for general use. Others when needed.

  4. Not labeling: Labels help identify. Use them.

  5. Formatting mounted filesystem: Unmount first. Then format.

Real-World Examples​

Format New Disk​

# List devices
lsblk

# Format
sudo mkfs.ext4 -L "backup" /dev/sdb1

# Mount
sudo mount /dev/sdb1 /backup

What's Next?​

Now that you can create filesystems, let's talk about Mounting to use them.

Personal note: When I started, I thought filesystems were complex. Then I realized: use ext4. It works. Learn others when you need them. Don't overthink it.