How to Create a New Disk Partition in Linux

create new disk partition linux

Storage devices such as a hard disk or USB drives need to structured before start using it. Partitioning is the process of slicing the disk into one more separate region called a partition. Most importantly a partition is required to install an operating system. The second common reason is that you can install multiple operating systems.

It is basically the first step for a newly installed disk. After creating a partition, the partition is formatted with a file system.

In this tutorial, I will go through steps to create a new partition on Linux distribution such as CentOS, Ubuntu, RHEL, and Debian.

1) List the partitions in Linux

To list the existing partition or block devices on your system you can use parted -l or fdisk -l or lsblk command. From this list, you can identify which disk you like to partition. The disk which is attached from storage devices (SANS) is normally visible in cat /proc/scsi/scsi or /proc/partitions file.

$ sudo parted -l

parted command to list disks

You can see unrecognized disk label error which indicates the new and unpartitioned disk.

$ sudo fdisk -l

fdisk list disks

$ sudo lsblk

lsblk command to list block devices

We have two disks attached our system, first disk /dev/xvda have the Operating system installed and the second is /dev/xvdb.

2) Disk partitioning in Linux

In the section, we'll create a single partition using the entire disk. Fdisk and parted are two tools used in Linux to create a disk partition. For creating partitions greater than 2 TB is not supported by fdisk.

Here, we will check how to create a partition using parted tool.

Set a partition type

The most common two partition types are MBR (msdos) and GPT. GPT uses more modern standard and MBR is supported across many operating systems.

If you don't have a special requirement, then you can opt for GPT standard.

$ sudo parted /dev/xvdb mklabel gpt
Output
ubuntu@linoxide:~$ sudo parted /dev/xvdb mklabel gpt
Information: You may need to update /etc/fstab.

Instead of a one-liner command, you can also run parted command in an interactive way. In the example, I am changing disk label to msdos which is MBR format.

$ sudo parted /dev/xvdb
GNU Parted 3.2
Using /dev/xvdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel msdos
Warning: The existing disk label on /dev/xvdb will be destroyed and all data on this
disk will be lost. Do you want to continue?
Yes/No? Y
(parted)

parted interactive create a disk label

For MBR type, run the following command:

$ sudo parted /dev/sda mklabel msdos

Creating a new partition

Even though the space for the new partition has been allocated and written to disk you still need to create a filesystem on that newly available space, so the next step is formatting the partition with the required filesystem.

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

If you check lsblk, can see a new partition /dev/xvdb1 listed:

list new partition - lsblk

Note: Parted defaults to '1000 kilobytes = 1 megabyte' and not '1024 kilobytes = 1 megabyte'.

If you run parted command again to list partition, you no longer see any error:

list new partition - parted

To slice the whole disk into multiple partitions, run mkpart specifying the size you want as follows:

(parted) mkpart primary ext4 0 1024MB
(parted) print

create partition with specific size
You can add more partitions based on your requirement as shown below:

(parted) mkpart primary ext4 1024MB 2048MB
(parted) print
Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdb: 8590MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name     Flags
 1      17.4kB  1024MB  1024MB  ext4         primary
 2      1024MB  2048MB  1023MB  ext4         primary

create more partitions

So we have created two primary partitions which are named shows as xvdb1 and xvdb2.

Note: For the MBR scheme you have a limit of 4 primary partitions but in GPT there are no such limits.

You may also use the following parted command to list partitions information on the disk.

$ sudo parted /dev/xvdb print

Output:

Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdb: 8590MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name     Flags
 1      17.4kB  1024MB  1024MB  ext4         primary
 2      1024MB  2048MB  1023MB  ext4         primary

Note: Type quit to exit out from parted prompt and whatever changes made will be saved.

3) Create a filesystem

Linux supports different filesystem type such as Ext2, Ext3, Ext4, BtrFS, and GlusterFS. In the previous section, we have created two new partitions and now we can format it as an Ext4 filesystem.

Linux has an inbuilt utility called mkfs.ext4, which can format a partition to Ext4 filesystem.

$ sudo mkfs.ext4 -L databackup /dev/xvdb1

mkfs ext4 format partitions

You can use -L option to set a partition label while formatting the partition.

Use e2label command to change the partition label as follows:

$ sudo e2label /dev/xvdb2 storagedata

To print all partition table information such as Name, FSTYPE, LABEL, UUID and MOUNTPOINT use lsblk --fs.

$ lsblk --fs
NAME    FSTYPE   LABEL           UUID                                 MOUNTPOINT
loop0   squashfs                                                      /snap/ssm-agent/1566
loop1   squashfs                                                      /snap/core/8935
xvda
└─xvda1 ext4     cloudimg-rootfs 6156ec80-9446-4eb1-95e0-9ae6b7a46187 /
xvdb
├─xvdb1 ext4     databackup      86d249af-ead2-41d4-9acd-296e36c63ec4
└─xvdb2 ext4     storagedata     beae745b-188f-41d2-a133-7c4212da0a34

4) Mount Filesystem

Finally, we are now going to mount the filesystem that enables to write data to mount point.

The following command will temporarily mount the filesystem:

$ sudo mount -t auto defaults /dev/xvdb1 /mnt/data

It's important to make sure that /etc/fstab file is updated to have newly created partitions get mounted automatically at boot time.

The fstab file should have any entry as follows:

LABEL=databackup /mnt/data ext4 defaults 0 2

or

/dev/xvdb1 /mnt/data ext4 defaults 0 2

Note: SCSI devices are identified as 'sd' and the letter immediately after 'sd' signifies the order in which it was first found. For example, sda1 means the first partition on the first drive. For explaining I have used Xen virtual disk which show devices as '/dev/xvd'.

To verify the filesystem is available use df command to list mounted partition and see its size.

$ df -h -x tmpfs -x devtmpfs -x squashfs

df -h command list mount point

Conclusion

In this tutorial, we learned how to partition, format, and mount a raw hard drive attached to the Linux system.

If you have any questions or feedback, feel free to leave a comment.

Related Read: How to Create Swap Partition on Linux
Bobbin Zachariah 9:09 pm

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2 Comments

  1. While attempting to write partition changes to disk for the initial Debian jessie install I receive an Input/Output error /dev/cciss/c0d0

    System is a HP ProLiant G4 with a Smart Array P400 controller.