Introduction

Managing disks and partitions is a core skill for any system administrator or power user. Whether preparing a fresh server, resizing filesystems on-the-fly, or recovering from a corrupted table, fdisk and parted are two of the most versatile command-line utilities available on Linux.

Understanding Disk Partitioning

Master Boot Record (MBR)

• Sector limit: Up to 2 TB per disk.
• Partition table: Located in the first 512 bytes.
• Max partitions: Four primary, or three primary one extended.
• Legacy compatibility: Well-supported by older BIOS systems.

GUID Partition Table (GPT)

• Sector limit: Virtually unlimited (up to 9.4 ZB).
• Partition table: Redundant headers at beginning and end.
• Max partitions: Typically 128 by default.
• UEFI requirement: Standard on modern systems for booting.

fdisk: A Traditional MBR Tool (and GPT-aware on Newer Releases)

Invoking fdisk

To examine all connected block devices:

sudo fdisk -l

To work on a specific disk:

sudo fdisk /dev/sdX

Common Interactive Commands

Non-Interactive Scripting

You can pipe commands via echo or use a here-document. Example:

sudo fdisk /dev/sdX ltltEOF
n
p
1

 10G
w
EOF
  

parted: Flexible GPT and MBR Management

Setting a Partition Table Label

parted supports both msdos (MBR) and gpt:

sudo parted /dev/sdX mklabel gpt
  

Interactive Mode

sudo parted /dev/sdX
(parted) print
(parted) mkpart primary ext4 1MiB 20GiB
(parted) set 1 boot on
(parted) quit
  

Non-Interactive Usage amp Units

By default, parted uses MiB and GiB. To work in sectors, bytes or percentages:

sudo parted -s /dev/sdX unit s mkpart primary ext4 2048 409600
  

Resizing Partitions and Filesystems

1. Unmount the filesystem: sudo umount /dev/sdX1
2. Resize partition: parted /dev/sdX resizepart 1 50GiB
3. Grow the filesystem: for ext4, sudo resize2fs /dev/sdX1

Aligning for Performance

Modern SSDs and RAID arrays benefit from proper alignment. Use MiB boundaries:

(parted) mkpart primary ext4 1MiB 100%
  

Best Practices and Caution

• Backup first: Always snapshot or image disks before modifying partitions.
• Double-check device names: Mixing up /dev/sda and /dev/sdb can be disastrous.
• Sync and refresh: Run sudo partprobe or reboot to ensure the kernel sees changes.
• Filesystem check: After resizing, run fsck to verify integrity.

Securing Remote Disk Management

When administering disks on remote servers, encryption and secure tunnels are vital. Typical workflow:

1. SSH into the server: ssh user@host
2. Use sudo fdisk or sudo parted as above.
3. Ensure your connection is protected by a VPN:

• NordVPN
• ExpressVPN
• ProtonVPN
• Surfshark

Conclusion

Mastering fdisk and parted gives you full control over disk layout, offering legacy compatibility and modern flexibility. By combining careful planning, best practices, and secure remote access (e.g., via a reputable VPN), you can confidently partition, resize, and maintain storage on any Linux system.