Using parted for Partitioning and LVM

Using `parted` for Partitioning and LVM

This page documents scriptable, exam-safe usage of parted for:

Standard disk partitioning
LVM‑ready partition creation
Safe automation patterns

Targeted for RHEL / Alma / Rocky / Debian and RHCSA 9 / 10 preparation.

parted only creates partitions.
Filesystems and LVM are created after partitioning.

Conceptual Flows

Standard Partition

parted → partition → mkfs → mount

LVM Partition

parted → LVM-marked partition → pvcreate → vgcreate → lvcreate → mkfs

1. Basic Non‑Interactive Partitioning (Recommended)

#!/bin/bash
set -e

DISK="/dev/sdb"

parted -s "$DISK" \
  mklabel gpt \
  mkpart primary xfs 1MiB 100%

partprobe "$DISK"

Notes

-s → script mode (non‑interactive)
1MiB start → avoids alignment issues
100% → uses entire disk

2. Multiple Standard Partitions

DISK=/dev/sdb

parted -s "$DISK" mklabel gpt
parted -s "$DISK" mkpart primary xfs 1MiB 2GiB
parted -s "$DISK" mkpart primary ext4 2GiB 6GiB
parted -s "$DISK" mkpart primary linux-swap 6GiB 100%

partprobe "$DISK"

mkfs.xfs  /dev/sdb1
mkfs.ext4 /dev/sdb2
mkswap    /dev/sdb3

3. LVM Partition (GPT – Recommended)

DISK=/dev/sdb

parted -s "$DISK" \
  mklabel gpt \
  mkpart primary 1MiB 100% \
  set 1 lvm on

partprobe "$DISK"

4. What the LVM Flag Does

Disk Label	Effect
GPT	Sets partition type to Linux LVM
MBR	Sets partition type to 0x8e

Helps tooling and admins identify intent
Not strictly required, but strongly recommended
RHCSA graders expect it

5. Full Workflow: Partition → LVM → Filesystem

DISK=/dev/sdb

# Partition
parted -s "$DISK" mklabel gpt
parted -s "$DISK" mkpart primary 1MiB 100%
parted -s "$DISK" set 1 lvm on
partprobe "$DISK"

# LVM
pvcreate /dev/sdb1
vgcreate vg_data /dev/sdb1
lvcreate -n lv_data -l 100%FREE vg_data

# Filesystem
mkfs.xfs /dev/vg_data/lv_data

6. Multiple LVM Partitions on One Disk

parted -s /dev/sdb mklabel gpt
parted -s /dev/sdb mkpart primary 1MiB 10GiB
parted -s /dev/sdb mkpart primary 10GiB 100%
parted -s /dev/sdb set 1 lvm on
parted -s /dev/sdb set 2 lvm on

pvcreate /dev/sdb1 /dev/sdb2
vgcreate vg_pool /dev/sdb1 /dev/sdb2

7. MBR (msdos) Example

parted -s /dev/sdb mklabel msdos
parted -s /dev/sdb mkpart primary 1MiB 100%
parted -s /dev/sdb set 1 lvm on

This sets partition type 8e.

8. Safe Automation Pattern (Abort if Disk Is Used)

DISK=/dev/sdb

if lsblk "$DISK" | grep -q part; then
  echo "Disk already partitioned — aborting"
  exit 1
fi

parted -s "$DISK" mklabel gpt
parted -s "$DISK" mkpart primary 1MiB 100%
parted -s "$DISK" set 1 lvm on
partprobe "$DISK"

9. Detect Disk Size Dynamically

SIZE=$(lsblk -b -dn -o SIZE /dev/sdb)

if (( SIZE < 20 * 1024 * 1024 * 1024 )); then
  echo "Disk too small"
  exit 1
fi

10. One‑Liner (Exam Speed)

parted -s /dev/sdb mklabel gpt mkpart primary 1MiB 100% set 1 lvm on && partprobe /dev/sdb

11. Verification Commands

lsblk
blkid
pvs
vgs
lvs

12. Common Mistakes (RHCSA Killers)

❌ Forgetting partprobe

❌ Forgetting to set the lvm flag

❌ Running pvcreate on the disk instead of the partition

❌ Creating a filesystem before LVM

❌ Using interactive fdisk in scripts

Summary

parted is scriptable and exam‑safe
Always align with 1MiB
Use GPT unless legacy requires MBR
Mark LVM partitions explicitly
Follow partition → LVM → filesystem order

Suitable for RHCSA 9 / 10 exam prep and real‑world automation.

Table of Contents

Using parted for Partitioning and LVM