Ubuntu resize an ext4 partition without LVM

This post will tell you how to make the partition extend to full disk after resizing the disk.

First, check current usage:

sudo df -Th

We will resize sdb1.

sudo fdisk /dev/sdb

n – Create partition
p – print partition table
g - reset as GPT partition table
d – delete a partition
q – exit without saving the changes
w – write the changes and exit.

Run:

This will delete the partiton. Select 1.

Run:

This will create a partiton. Select the start point and end point. Start should be the original start. End should be the end of the disk. Usually you can keep those values default.

Run:

To write those changes to partition table.

Run:

sudo resize2fs /dev/sdb1

To make file system understand that partiton table is changed.

Run:

sudo df -Th

To see if the system recognize the new partiton. (You may need rebooting to see the size changes)

Full demo:

Welcome to Ubuntu 22.04.1 LTS (GNU/Linux 5.15.0-48-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Fri Oct  7 06:22:25 PM UTC 2022

  System load:  2.16015625         Processes:               414
  Usage of /:   26.5% of 62.69GB   Users logged in:         0
  Memory usage: 5%                 IPv4 address for ens160: 192.168.50.31
  Swap usage:   0%

 * Super-optimized for small spaces - read how we shrank the memory
   footprint of MicroK8s to make it the smallest full K8s around.

   https://ubuntu.com/blog/microk8s-memory-optimisation

0 updates can be applied immediately.


Web console: https://nextcloud:9090/ or https://192.168.50.31:9090/

Last login: Fri Oct  7 17:08:07 2022 from 192.168.50.121
anduin@nextcloud:~$ sudo df -Th
Filesystem              Type   Size  Used Avail Use% Mounted on
tmpfs                   tmpfs  1.6G  1.4M  1.6G   1% /run
/dev/sda2               ext4    63G   17G   43G  28% /
tmpfs                   tmpfs  7.9G     0  7.9G   0% /dev/shm
tmpfs                   tmpfs  5.0M     0  5.0M   0% /run/lock
/dev/sdb1               ext4   885G  393G  447G  47% /mnt/datastorage
//vault/Shared          cifs   3.5T  1.2T  2.4T  32% /mnt/Shared
//vault/NextcloudBackup cifs   3.5T  1.2T  2.4T  32% /mnt/Backup
tmpfs                   tmpfs  1.6G  4.0K  1.6G   1% /run/user/1000
anduin@nextcloud:~$ sudo fdisk /dev/sdb

Welcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

GPT PMBR size mismatch (1887436799 != 8589934591) will be corrected by write.
This disk is currently in use - repartitioning is probably a bad idea.
It's recommended to umount all file systems, and swapoff all swap
partitions on this disk.


Command (m for help): p

Disk /dev/sdb: 4 TiB, 4398046511104 bytes, 8589934592 sectors
Disk model: Virtual disk
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: DDBA19F6-857E-E048-81F6-A9E61B90C683

Device     Start        End    Sectors  Size Type
/dev/sdb1   2048 1887436766 1887434719  900G Linux filesystem

Command (m for help): d
Selected partition 1
Partition 1 has been deleted.

Command (m for help): n
Partition number (1-128, default 1):
First sector (2048-8589934558, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-8589934558, default 8589934558):

Created a new partition 1 of type 'Linux filesystem' and of size 4 TiB.
Partition #1 contains a ext4 signature.

Do you want to remove the signature? [Y]es/[N]o: N

Command (m for help): p

Disk /dev/sdb: 4 TiB, 4398046511104 bytes, 8589934592 sectors
Disk model: Virtual disk
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: DDBA19F6-857E-E048-81F6-A9E61B90C683

Device     Start        End    Sectors Size Type
/dev/sdb1   2048 8589934558 8589932511   4T Linux filesystem

Command (m for help): w
The partition table has been altered.
Syncing disks.

anduin@nextcloud:~$ sudo resize2fs /dev/sdb1
resize2fs 1.46.5 (30-Dec-2021)
Filesystem at /dev/sdb1 is mounted on /mnt/datastorage; on-line resizing required
old_desc_blocks = 113, new_desc_blocks = 512
The filesystem on /dev/sdb1 is now 1073741563 (4k) blocks long.

anduin@nextcloud:~$ sudo df -Th
Filesystem              Type   Size  Used Avail Use% Mounted on
tmpfs                   tmpfs  1.6G  1.4M  1.6G   1% /run
/dev/sda2               ext4    63G   17G   43G  28% /
tmpfs                   tmpfs  7.9G     0  7.9G   0% /dev/shm
tmpfs                   tmpfs  5.0M     0  5.0M   0% /run/lock
/dev/sdb1               ext4   4.0T  393G  3.4T  11% /mnt/datastorage
//vault/Shared          cifs   3.5T  1.2T  2.4T  32% /mnt/Shared
//vault/NextcloudBackup cifs   3.5T  1.2T  2.4T  32% /mnt/Backup
tmpfs                   tmpfs  1.6G  4.0K  1.6G   1% /run/user/1000

let today = new Beginning();