Parted

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Parted

How To Partition and Format Storage Devices in Linux

Introduction

Preparing a new disk for use on a Linux system is a straightforward process. There are many tools, filesystem formats, and partitioning schemes that may change the process if you have specialized needs, but the fundamentals remain the same.

This guide will cover the following process:

  • Identifying the new disk on the system.

  • Creating a single partition that spans the entire drive (most operating systems expect a partition layout, even if only one filesystem is present)

  • Formatting the partition with the Ext4 filesystem (the default in most modern Linux distributions)

  • Mounting and setting up Auto-mounting of the filesystem at boot

Step 1 Install Parted

To partition the drive, you’ll use the parted utility. Most of the commands necessary for interacting with a low-level filesystem are available by default on Linux. parted, which creates partitions, is one of the only occasional exceptions.

If you are on an Ubuntu or Debian server and do not have parted installed, you can install it by typing:

sudo apt update
sudo apt install parted

If you are on an RHEL, Rocky Linux, or Fedora server, you can install it by typing:

sudo dnf install parted

Every other command used in this tutorial should be preinstalled, so you can move on to the next step.

Step 2 Identify the New Disk on the System

Before you set up the drive, you need to be able to properly identify it on the server.

If this is a completely new drive, One way to identify it on your server is to look for the absence of a partitioning scheme. If you ask parted to list the partition layout of your disks, it will produce an error for any disks that don’t have a valid partition scheme. This can be used to help identify the new disk:

sudo parted -l | grep Error

You should see an unrecognized disk label error for the new, unpartitioned disk:

OutputError: /dev/sda: unrecognized disk label

You can also use the lsblk command and look for a disk of the correct size that has no associated partitions:

lsblk

OutputNAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0   100G  0 disk
vda    253:0    0    20G  0 disk
└─vda1 253:1    0    20G  0 part /

Note: Remember to check lsblk every time you reconnect to your server before making changes. The /dev/sd* and /dev/hd* disk identifiers will not necessarily be consistent between boots, which means there is some danger of partitioning or formatting the wrong disk if you do not verify the disk identifier correctly.

Consider using more persistent disk identifiers like /dev/disk/by-uuid, /dev/disk/by-label, or /dev/disk/by-id.

When you know the name that the kernel has assigned your disk, you can partition your drive.

Step 3 Partition the New Drive

As mentioned in the introduction, you’ll create a single partition spanning the entire disk in this guide.

Choose a Partitioning Standard

To do this, you first need to specify the partitioning standard to use. There are two options: GPT and MBR. GPT is a more modern standard, while MBR is more widely supported among older operating systems. For a typical cloud server, GPT is a better option.

To choose the GPT standard, pass the disk you identified to parted with mklabel gpt:

sudo parted /dev/sda mklabel gpt

To use the MBR format, use mklabel msdos:

sudo parted /dev/sda mklabel msdos

Create the New Partition

Once the format is selected, you can create a partition spanning the entire drive by using parted -a:

sudo parted -a opt /dev/sda mkpart primary ext4 0% 100%

You can break down this command as follows:

  • parted -a opt runs parted, setting the default optimal alignment type.

  • /dev/sda is the disk that you’re partitioning.

  • mkpart primary ext4 makes a standalone (i.e. bootable, not extended from another) partition, using the ext4 filesystem.

  • 0% 100% means that this partition should span from the start to the finish of the disk.

For more information, refer to the manual page of Parted.

If you check lsblk, you should see the new partition available:

lsblk

OutputNAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0   100G  0 disk
└─sda1   8:1    0   100G  0 part
vda    253:0    0    20G  0 disk
└─vda1 253:1    0    20G  0 part /

You now have a new partition created, but it has not yet been initialized as a filesystem. The difference between these two steps is somewhat arbitrary, and unique to the way Linux filesystems work, but they are still two steps in practice.

Step 4 Create a Filesystem on the New Partition

Now that you have a partition available, you can initialize it as an Ext4 filesystem. Ext4 is not the only filesystem option available, but it is the most straightforward option for a single, standalone Linux volume. Windows uses filesystems like NTFS and exFAT, but they have limited support on other platforms (meaning that they will be read-only in some contexts, and cannot be used as a boot drive for other operating systems), and macOS uses HFS+ and APFS, with the same caveats. There are also newer Linux filesystems than Ext4, such as ZFS and BTRFS, but these impose different requirements and they are generally better-suited to multi-disk arrays.

To initialize an Ext4 filesystem, use the mkfs.ext4 utility. You can add a partition label with the -L flag. Select a name that will help you identify this particular drive:

Note: Make sure you provide the path to the partition and not the entire disk. In Linux, disks have names like sda, sdb, hda, etc. The partitions on these disks have a number appended to the end. So you would want to use something like sda1, not sda.

sudo mkfs.ext4 -L datapartition /dev/sda1

If you want to change the partition label later on, you can use the e2label command:

sudo e2label /dev/sda1 newlabel

You can see all of the different ways to identify your partition with lsblk. You should find the name, label, and UUID of the partition.

Some versions of lsblk will print all of this information with the --fs argument:

sudo lsblk --fs

You can also specify them manually with lsblk -o followed by the relevant options:

sudo lsblk -o NAME,FSTYPE,LABEL,UUID,MOUNTPOINT

You should receive output like this. The highlighted output indicate different methods you can use to refer to the new filesystem:

OutputNAME   FSTYPE LABEL         UUID                                 MOUNTPOINT
sda
└─sda1 ext4   datapartition 4b313333-a7b5-48c1-a957-d77d637e4fda
vda
└─vda1 ext4   DOROOT        050e1e34-39e6-4072-a03e-ae0bf90ba13a /

Make a note of this output, as you’ll use it when mounting the filesystem in the next step.

Step 5 Mount the New Filesystem

Now, you can mount the filesystem for use.

The Filesystem Hierarchy Standard recommends using the /mnt directory or a subdirectory under it for temporarily mounted filesystems (like removable drives). It makes no recommendations on where to mount more permanent storage, so you can choose whichever scheme you’d like. For this tutorial, you’ll mount the drive under /mnt/data.

Create that directory using mkdir:

sudo mkdir -p /mnt/data

Mounting the Filesystem Temporarily

You can mount the filesystem temporarily by typing:

sudo mount -o defaults /dev/sda1 /mnt/data

Mounting the Filesystem Automatically at Boot

In order to mount the filesystem automatically each time the server boots, you’ll add an entry to the /etc/fstab file. This file contains information about all of your system’s permanent, or routinely mounted, disks. Open the file using nano or your favorite text editor:

sudo nano /etc/fstab

In the last step, you used the sudo lsblk --fs command to display identifiers for your filesystem. You can use any of these in this file. This example uses the partition label, but you can see what the lines would look like using the other two identifiers in the commented out lines:

# /etc/fstab
    ## Use one of the identifiers you found to reference the correct partition
    # /dev/sda1 /mnt/data ext4 defaults 0 2
    # UUID=4b313333-a7b5-48c1-a957-d77d637e4fda /mnt/data ext4 defaults 0 2
    LABEL=datapartition /mnt/data ext4 defaults 0 2

Beyond the LABEL=datapartition element, these options work as follows:

  • /mnt/data is the path where the disk is being mounted.

  • ext4 connotes that this is an Ext4 partition.

  • defaults means that this volume should be mounted with the default options, such as read-write support.

  • 0 2 signifies that the filesystem should be validated by the local machine in case of errors, but as a 2nd priority, after your root volume.

Note: You can learn about the various fields in the /etc/fstab file by checking its man page For information about the mount options available for a specific filesystem type, check man [filesystem] (like man ext4).

Save and close the file when you are finished. If you are using nano, press Ctrl+X, then when prompted to confirm, Y and then Enter.

If you did not mount the filesystem previously, you can now mount it with mount -a:

sudo mount -a

Testing the Mount

After you’ve mounted the volume, we should check to make sure that the filesystem is accessible.

You can check if the disk is available in the output from the df command. Sometimes df will include unnecessary information about temporary filesystems called tmpfs in df output, which you can exclude by appending -x tmpfs:

df -h -x tmpfs

OutputFilesystem      Size  Used Avail Use% Mounted on
/dev/vda1        20G  1.3G   18G   7% /
/dev/sda1        99G   60M   94G   1% /mnt/data

You can also check that the disk mounted with read and write capabilities by writing to a test file:

echo "success" | sudo tee /mnt/data/test_file

Read the file back just to make sure the write executed correctly:

cat /mnt/data/test_file
Outputsuccess

You can remove the file after you have verified that the new filesystem is functioning correctly:

sudo rm /mnt/data/test_file

Conclusion

Your new drive should now be partitioned, formatted, mounted, and ready for use. This is the general process you can use to turn a raw disk into a filesystem that Linux can use for storage. There are more complex methods of partitioning, formatting, and mounting which may be more appropriate in some cases, but the above is a good starting point for general use.

Next, you may want to learn how to use SSHFS to mount remote volumes over SSH.

Last update: Nov 20, 2024