Wednesday 27 May 2020

How to format disk larger than 2TB in Linux

Traditionally I used to use fdisk to do so (here), but it is limited to 2TB disks.

These tips are from techmint with some modification.
apt-get install parted 

1. Check Parted Version

Run the following command, you see message similar to the one shown on the image below. Don’t worry if your parted version is different. Unless specified otherwise, parted will use your primary drive, which in most cases will be /dev/sda.
$ parted
Check Parted Command Version
Check Parted Command Version
If you want to exit parted, simply type:
$ quit

2. List Linux Disk Partitions

Now that parted is started, let’s list the partitions of the selected hard disk. As mentioned earlier, parted chooses your first drive by default. To see the disk partitions run print.
(parted) print
Check Linux Partitions
Check Linux Partitions
When running print, it will also display the hard disk information and model. Here is example from a real hard disk (not virtual as shown on the image above) :
(parted) print

Model: ATA TOSHIBA MQ01ACF0 (scsi)
Disk /dev/sda: 320GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos

Number  Start   End    Size   Type      File system  Flags

 1      1049kB  256MB  255MB  primary   ext2         boot
 2      257MB   320GB  320GB  extended
 5      257MB   320GB  320GB  logical                lvm
In the example above, you can see the disk model, capacity sector size and partition table.

3. List or Switch to Different Disk

If you have more than one hard disk, you can easily switch between disks, by using the “select” command. In the example below, I will switch from /dev/sda to /dev/sdb which is a secondary drive on my system.
To easily switch between disks you can use:
(parted) select /dev/sdX
Select Different Disk
Select Different Disk
Change "X" with the letter of the disk to which you wish to switch.

4. Create Primary or Logical Partition in Linux

Parted can be used to create primary and logical disk partitions. In this example, I will show you how to create primary partition, but the steps are the same for logical partitions.
To create new partition, parted uses “mkpart“. You can give it additional parameters like "primary" or "logical" depending on the partition type that you wish to create.
Before you start creating partitions, it’s important to make sure that you are using (you have selected) the right disk.
Start by using print:
(parted) print
Show Current Linux Disk
Show Current Linux Disk
As shown on the above image, we are using a virtual drive of 34 GB. First we will give the new disk a label and then create a partition and set a file system on it.
Now the first step is to give the new disk a label name with:
(parted) mklabel gpt  #Note: msdos is not suitble for > 2TBs
Now create the new partition with  mkpart. The listed units are in megabytes (MB). We will create a 10 GB partition starting from 1 to 10000:
(parted) mkpart 0% 100% primary 

Create Primary or Logical Linux Partitions
Create Primary or Logical Linux Partitions
Next,  exit parted with "quit" command. We will format our new partition in ext4 file system using mkfs. To make this happen run the following command:
# mkfs.ext4 /dev/sdb1
Note: It’s important to select the right disk and partition when executing the above command!
Now let’s verify our results, by printing the partition table on our secondary disk. Under file system column, you should see ext4 or the file system type that you have decided to use for your partition:
Verify Disk Partition Filesystem
Verify Disk Partition Filesystem

5. Resize Linux Disk Partition

Parted includes multiple useful functions and one of them is "resizepart". As you have probably figured this out by now, "resizepart" helps you resize a partition.
In the example below, you will see how to resize an existing partition. For the purpose of this example, we will be using the earlier created partition.
First you will need to know the number of the partition that you will be resizing. This can be easily found by using "print":
(parted) print
Find Linux Partition Number
Find Linux Partition Number
In our example, the partition number is "1". Now run the resizepart command:
(parted) resizepart
You will be asked for the number of the partition that you will resize. Enter it’s number. After that, you will be asked to set the new ending point for this partition. Remember that by default the units are in MB. In our example, we have set the new partition size to 15 GB:
(parted) resizepart 
Partition number? 1
End?  [10.0GB]? 15000
Now verify the results with "print":
(parted) print
Verify Linux Resize Partition
Verify Linux Resize Partition

6. Delete Linux Partition

The next thing you will learn is how to delete a partition from your hard drive. To do this, you will need to use the "rm" command within parted. To delete a disk partition you will need to know it’s number.
As mentioned earlier, you can easily obtain this number by using "print". In our example, we will delete the partition with number 1 from our secondary drive /dev/sdb1:
(parted) rm 1
Verify the results by printing the partitions table:
Delete a Linux Partition
Delete a Linux Partition

7. Rescue Linux Disk Partition

Parted supports a “rescue" utility that helps you recover a lost partition between a starting and ending point. If a partition is found within that range, it will attempt to restore it.
Here is an example:
(parted) rescue
Start? 1
End? 15000
(parted) print
Model: Unknown (unknown)
Disk /dev/sdb1: 15.0GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:

Number Start End Size File system Flags
1 0.00B 15.0GB 15.0GB ext4

8 Change Linux Partition Flag

Using parted, you can change the state of a flag for disk partitions. The supported flags are:
  1. boot
  2. root
  3. swap
  4. hidden
  5. raid
  6. lvm
  7. lba
  8. legacy_boot
  9. irst
  10. esp
  11. palo
The states can be either "on" or "off". To change a flag simply run "set" command within parted:
(parted) set 2 lba on
The above command sets lba flag to on for second partition. Verify the results with print:
Change Partition Flag
Change Partition Flag

Conclusion

Parted is a useful and powerful utility that can help you manage your disk partitions in Linux systems. As always, when working with disk partitions you need to be extra careful. It is strongly recommend to go through parted man pages to learn how you can customize it’s output and find more information about its capabilities.
If you have any questions or comments, please do not hesitate to use the comment section below.