Split a Drive into Multiple Partitions And Format Them as Ext4 and Btrfs

This challenge builds upon the basic GPT partitioning challenge by introducing multiple partitions with different filesystems.

Real-world servers often need their storage divided for different purposes: fast, journaled filesystems like ext4 for logs and system data, and advanced filesystems like btrfs for application data that benefits from features like snapshots, compression, and copy-on-write semantics.

Device names on the diagram are deliberately generic.

Your mission is to:

1. Create a GUID partition table (GPT) on the blank 40 GiB drive.
2. Add a first partition of exactly 10 GiB for log storage.
3. Add a second partition using the remaining ~30 GiB for data storage.
4. Format the first partition as ext4 and mount it at /var/log/acme.
5. Format the second partition as btrfs and mount it at /var/lib/acme.
6. Write test files: service.log in the logs partition and dataset.txt in the data partition.

sudo apt-get update
sudo apt-get install btrfs-progs

This challenge demonstrates advanced disk partitioning by creating multiple partitions with different filesystems on a single drive. You'll create a 10 GiB ext4 partition for logs and use the remaining space for a btrfs data partition.

Here's a step-by-step solution using parted:

Step 1: Identify the Blank Drive

First, identify the blank drive that needs to be partitioned:

lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vda  253:0    0  10G  0 disk /
vdb  253:16   0  40G  0 disk

The /dev/vdb device is our 40 GiB blank drive with no partitions.

Step 2: Install Required Tools

Install the necessary partitioning and filesystem tools:

sudo apt-get update
sudo apt-get install -y parted btrfs-progs

• parted: For creating GPT partition tables and partitions
• btrfs-progs: For creating and managing btrfs filesystems

Step 3: Create a GUID Partition Table

Initialize the disk with a GUID partition table (GPT):

sudo parted /dev/vdb mklabel gpt

This creates a new GPT on the disk, erasing any existing partition table.

Step 4: Create the First Partition (10 GiB for Logs)

Create the first partition with exactly 10 GiB for log storage:

sudo parted /dev/vdb mkpart primary ext4 0% 10GiB

This command:

• Creates a new partition (mkpart)
• Names it primary (on MBR disks, this word sets the partition type, but on GPT disks it becomes the partition name)
• Labels it for ext4 filesystem
• Uses space from 0% to 10 GiB (parted starts the partition at 1 MiB for alignment, so it is 1 MiB smaller than 10 GiB)

Step 5: Create the Second Partition (Remaining Space for Data)

Create the second partition using all remaining space:

sudo parted /dev/vdb mkpart primary btrfs 10GiB 100%

This command:

• Creates another partition starting where the first one ended
• Uses space from 10 GiB to 100% of the disk
• Labels it for btrfs filesystem

Step 6: Verify the Partition Layout

Check the partition table:

sudo parted /dev/vdb print

You should see output like:

Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 42.9GB
Sector size (logical/physical): 512B/16384B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name     Flags
 1      1049kB  10.7GB  10.7GB               primary
 2      10.7GB  42.9GB  32.2GB               primary

Step 7: Update the Kernel Partition Table

parted tells the kernel about the new partitions itself, so /dev/vdb1 and /dev/vdb2 usually show up right away. If they don't, ask the kernel to update its view of the partition table:

sudo partx -u /dev/vdb

Step 8: Verify Partitions Are Visible

Check that both partitions are now visible:

lsblk

NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vda    253:0    0  10G  0 disk /
vdb    253:16   0  40G  0 disk
├─vdb1 253:17   0  10G  0 part
└─vdb2 253:18   0  30G  0 part

Perfect! Both /dev/vdb1 (10G) and /dev/vdb2 (30G) are visible.

Step 9: Format the First Partition with ext4

Format the 10 GiB partition for log storage:

sudo mkfs.ext4 /dev/vdb1

The ext4 filesystem is ideal for logs because:

• Fast sequential writes
• Excellent journaling for crash recovery
• Well-tested and stable

Step 10: Format the Second Partition with btrfs

Format the larger partition for data storage:

sudo mkfs.btrfs /dev/vdb2

The btrfs filesystem offers advanced features:

• Copy-on-write semantics
• Built-in compression
• Snapshot capabilities
• Subvolumes for organization

Step 11: Create Mount Points

Create the directories where the partitions will be mounted:

sudo mkdir -p /var/log/acme
sudo mkdir -p /var/lib/acme

Step 12: Mount Both Partitions

Mount the ext4 partition for logs:

sudo mount /dev/vdb1 /var/log/acme

Mount the btrfs partition for data:

sudo mount /dev/vdb2 /var/lib/acme

Step 13: Verify Mounts

Check that both partitions are properly mounted:

mount | grep vdb

/dev/vdb1 on /var/log/acme type ext4 (rw,relatime,stripe=4)
/dev/vdb2 on /var/lib/acme type btrfs (rw,relatime,space_cache=v2,subvolid=5,subvol=/)

You can also use:

df -h

Step 14: Create Test Files

Create the required test files to prove both filesystems work:

Create a log file on the ext4 partition:

echo "Service started successfully" | sudo tee /var/log/acme/service.log

Create a data file on the btrfs partition:

echo "Important dataset stored on btrfs" | sudo tee /var/lib/acme/dataset.txt

Step 15: Verify the Setup

Verify both files were created successfully:

cat /var/log/acme/service.log
cat /var/lib/acme/dataset.txt

Check filesystem types:

lsblk -f

NAME   FSTYPE FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
vda    ext4   1.0         e7ecc123-9abd-4733-bb92-72e3e4aeed24    7.5G    18% /
vdb
├─vdb1 ext4   1.0         f6a33a7a-9077-4a96-9bca-8a777fef2ad3    9.2G     0% /var/log/acme
└─vdb2 btrfs              6c3de97c-7878-445c-9fc6-0b758072e0d5   29.5G     0% /var/lib/acme

This solution demonstrates the same multi-partition setup using gdisk and its scriptable counterpart sgdisk. While parted is a general-purpose tool, gdisk is specialized for GPT partitions and offers more advanced features for GPT management.

Here's a step-by-step solution using the gdisk family of tools:

Step 1: Identify the Blank Drive

First, identify the blank drive that needs to be partitioned:

lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vda  253:0    0  10G  0 disk /
vdb  253:16   0  40G  0 disk

The /dev/vdb device is our 40 GiB blank drive with no partitions.

Step 2: Install Required Tools

Install the necessary partitioning and filesystem tools:

sudo apt-get update
sudo apt-get install -y gdisk btrfs-progs

• gdisk: GPT-specific partitioning tools (includes gdisk, cgdisk, and sgdisk)
• btrfs-progs: For creating and managing btrfs filesystems

Understanding the gdisk Family

The gdisk package provides three related tools:

• gdisk: Interactive command-line tool (like fdisk but for GPT)
• cgdisk: Curses-based TUI version
• sgdisk: Scriptable command-line tool (perfect for automation)

We'll use sgdisk for this solution since it's ideal for scripts and automation.

Step 3: Clear Existing Data and Create GPT

Clear any existing partition table and create a fresh GPT:

sudo sgdisk --clear /dev/vdb

This command:

• Removes any existing partition table (MBR or GPT)
• Creates a new, empty GPT structure
• Initializes the protective MBR

Step 4: Create the First Partition (10 GiB for Logs)

Create a 10 GiB partition for log storage:

sudo sgdisk --new=1:0:+10GiB \
      --typecode=1:8300 \
      --change-name=1:'Log Storage' \
      /dev/vdb

This command breakdown:

• --new=1:0:+10GiB: Create partition 1, starting at sector 0 (auto-aligned), size +10GiB
• --typecode=1:8300: Set partition type to Linux filesystem (hex code 8300)
• --change-name=1:'Log Storage': Give the partition a descriptive name

Step 5: Create the Second Partition (Remaining Space for Data)

Create the second partition using all remaining space:

sudo sgdisk --new=2:0:0 \
      --typecode=2:8300 \
      --change-name=2:'Data Storage' \
      /dev/vdb

This command breakdown:

• --new=2:0:0: Create partition 2, auto-start, use all remaining space (0 = max)
• --typecode=2:8300: Linux filesystem type
• --change-name=2:'Data Storage': Descriptive name

Step 6: Verify the Partition Layout

Check the partition table using gdisk in list mode:

sudo gdisk -l /dev/vdb

You should see output like:

GPT fdisk (gdisk) version 1.0.10

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/vdb: 83886112 sectors, 40.0 GiB
Sector size (logical/physical): 512/16384 bytes
Disk identifier (GUID): 51CE473C-7222-4C37-BD44-E12FFA2ED5BC
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 83886078
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048        20973567   10.0 GiB    8300  Log Storage
   2        20973568        83886078   30.0 GiB    8300  Data Storage

Alternative: Interactive gdisk Method

If you prefer an interactive approach, you can use gdisk directly:

sudo gdisk /dev/vdb

Then follow these commands in the interactive prompt:

1. o - Create new empty GUID partition table
2. n - Add new partition (accept the defaults, but enter +10G as the last sector)
3. n - Add second partition (accept defaults for remaining space)
4. w - Write table to disk and exit

Step 7: Update the Kernel Partition Table

sgdisk and gdisk ask the kernel to re-read the partition table after writing it, so /dev/vdb1 and /dev/vdb2 usually show up right away. If they don't, ask the kernel to update its view of the partition table:

sudo partx -u /dev/vdb

Step 8: Verify Partitions Are Visible

Check that both partitions are now visible:

lsblk

NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vda    253:0    0  10G  0 disk /
vdb    253:16   0  40G  0 disk
├─vdb1 253:17   0  10G  0 part
└─vdb2 253:18   0  30G  0 part

Perfect! Both partitions are visible with the expected sizes.

Step 9: Format the Partitions

Format the first partition with ext4 for log storage:

sudo mkfs.ext4 /dev/vdb1

Format the second partition with btrfs for data storage:

sudo mkfs.btrfs /dev/vdb2

Step 10: Create Mount Points

Create the directories where the partitions will be mounted:

sudo mkdir -p /var/log/acme
sudo mkdir -p /var/lib/acme

Step 11: Mount Both Partitions

Mount the ext4 partition for logs:

sudo mount /dev/vdb1 /var/log/acme

Mount the btrfs partition for data:

sudo mount /dev/vdb2 /var/lib/acme

Step 12: Verify Mounts

Check that both partitions are properly mounted:

mount | grep vdb

You should see:

/dev/vdb1 on /var/log/acme type ext4 (rw,relatime,stripe=4)
/dev/vdb2 on /var/lib/acme type btrfs (rw,relatime,space_cache=v2,subvolid=5,subvol=/)

Step 13: Create Test Files

Create the required test files:

echo "Service logs initialized on ext4 partition" | sudo tee /var/log/acme/service.log
echo "Data storage ready on btrfs partition" | sudo tee /var/lib/acme/dataset.txt

Step 14: Verify the Complete Setup

Check filesystem information:

lsblk -f

NAME   FSTYPE FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
vda    ext4   1.0         e7ecc123-9abd-4733-bb92-72e3e4aeed24    7.5G    18% /
vdb
├─vdb1 ext4   1.0         f6a33a7a-9077-4a96-9bca-8a777fef2ad3    9.2G     0% /var/log/acme
└─vdb2 btrfs              6c3de97c-7878-445c-9fc6-0b758072e0d5   29.5G     0% /var/lib/acme

Verify the test files:

cat /var/log/acme/service.log
cat /var/lib/acme/dataset.txt