How To Partition and Format Storage Devices in Linux
Introduction
Preparing a new disk for use on a Linux system can be quick and easy. There are many tools, filesystem formats, and partitioning schemes that may complicate the process if you have specialized needs, but if you want to get up and running quickly, it's fairly straightforward.
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
Install the Tools
To partition the drive, we'll use the parted
utility. In most cases, this will already be installed on the server.
If you are on an Ubuntu or Debian server and do not have parted
yet, you can install it by typing:
- sudo apt-get update
- sudo apt-get install parted
If you are on a CentOS or Fedora server, you can install it by typing:
- sudo yum install parted
Identify the New Disk on the System
Before we set up the drive, we need to be able to properly identify it on the server.
If this is a completely new drive, the easiest way to find it on your server may be to look for the absence of a partitioning scheme. If we ask parted
to list the partition layout of our disks, it will give us an error for any disks that don't have a valid partition scheme. This can be used to help us 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: unrecognised 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 /
Remember to check lsblk
in every session 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
. See our introduction to storage concepts and terminology in Linux article for more information.
When you know the name the kernel has assigned your disk, you can partition your drive.
Partition the New Drive
As mentioned in the introduction, we'll create a single partition spanning the entire disk in this guide.
Choose a Partitioning Standard
To do this, we first need to specify the partitioning standard we wish to use. GPT is the more modern partitioning standard, while the MBR standard offers wider support among operating systems. If you do not have any special requirements, it is probably better to use GPT at this point.
To choose the GPT standard, pass in the disk you identified like this:
- sudo parted /dev/sda mklabel gpt
If you wish to use the MBR format, type this instead:
- 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 typing:
- sudo parted -a opt /dev/sda mkpart primary ext4 0% 100%
If we check lsblk
, we 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 /
Create a Filesystem on the New Partition
Now that we have a partition available, we can format it as an Ext4 filesystem. To do this, pass the partition to the mkfs.ext4
utility.
We can add a partition label by passing the -L
flag. Select a name that will help you identify this particular drive:
sda
, sdb
, hda
, etc. The partitions on these disks have a number appended to the end. So we would want to use something like sda1
and not sda
.- sudo mkfs.ext4 -L datapartition /dev/sda1
If you want to change the partition label at a later date, 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
. We want to find the name, label, and UUID of the partition.
Some versions of lsblk
will print all of this information if we type:
- sudo lsblk --fs
If your version does not show all of the appropriate fields, you can request them manually:
- sudo lsblk -o NAME,FSTYPE,LABEL,UUID,MOUNTPOINT
You should see something 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 /
Mount the New Filesystem
Now, we can mount the filesystem for use.
The Filesystem Hierarchy Standard recommends using /mnt
or a subdirectory under it for temporarily mounted filesystems. It makes no recommendations on where to mount more permanent storage, so you can choose whichever scheme you'd like. For this tutorial, we'll mount the drive under /mnt/data
.
Create the directory by typing:
- 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
If you wish to mount the filesystem automatically each time the server boots, adjust the /etc/fstab
file:
- sudo nano /etc/fstab
Earlier, we issued a sudo lsblk --fs
command to display three filesystem identifiers for our filesystem. We can use any of these in this file. We've used the partition label below, but you can see what the lines would look like using the other two identifiers in the commented out lines:
. . .
## 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
You can learn about the various fields in the /etc/fstab
file by typing man fstab
. For information about the mount options available for a specific filesystem type, check man [filesystem]
(like man ext4
). For now, the mount lines above should get you started.
For SSDs, the discard
option is sometimes appended to enable continuous TRIM. There is debate over the performance and integrity impacts of performing continuous TRIM in this manner, and most distributions include method of performing periodic TRIM as an alternative.
Save and close the file when you are finished.
If you did not mount the filesystem previously, you can now mount it by typing:
sudo mount -a
Testing the Mount
After we've mounted the volume, we should check to make sure that the filesystem is accessible.
We can check if the the disk is available in the output from the df
command:
- df -h -x tmpfs -x devtmpfs
OutputFilesystem Size Used Avail Use% Mounted on
/dev/vda1 20G 1.3G 18G 7% /
/dev/sda1 99G 60M 94G 1% /mnt/data
You should also be able to see a lost+found
directory within the /mnt/data
directory, which typically indicates the root of an Ext* filesystem:
- ls -l /mnt/data
Outputtotal 16
drwx------ 2 root root 16384 Jun 6 11:10 lost+found
We can also check that the file 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 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.
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