Resize partitions and file systems of Linux system disks

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Last Updated: Sep 09, 2019 Edit in Github

This topic describes how to use the growpart and resize2fs tools to resize the partitions and extend the file systems of Linux system disks.

Application scope

The procedures in this topic apply to system disks with the following partition formats and file system formats:

Partitions: MBR and GPT
File systems: ext*, XFS, and Btrfs

Preparations

Create a snapshot for data backup, to prevent data loss caused by misoperations.
Use the ECS console or API to Resize cloud disks offline.
Connect to the ECS instance remotely. For more information about connection methods, see Methods to connect to an ECS instance.
Install the growpart or xfsprogs tool based on your operating system.
- In CentOS 7 and Aliyun Linux, run the following commands:
```
yum install cloud-utils-growpart
yum install xfsprogs
```
- In Ubuntu 14, Ubuntu 16, Ubuntu 18 and Debian 9, run the following commands:
```
apt install cloud-guest-utils
apt install xfsprogs
```
- In Debian 8, openSUSE 42.3, openSUSE 13.1, and SUSE Linux Enterprise Server 12 SP2, use an upstream version of growpart or xfsprogs.
Check the kernel version of your instance, for example, by running the uname -a command.
- For kernels 3.6.0 or later, see Procedure for instances with kernels 3.6.0 or later.
- For kernels earlier than 3.6.0, see Procedure for instances with kernels earlier than 3.6.0. If your instance runs a Linux distribution such as CentOS 6, Debian 7, or SUSE Linux Enterprise Server 11 SP4, the instance must be restarted by using the console or an API operation before resizing can be completed.

Procedure for instances with kernels 3.6.0 or later

This procedure uses an instance running CentOS 7 to describe how to resize a system disk partition.

Run the fdisk -l command to check the size of the disk.

In this example, the /dev/vda disk size is 100 GiB.

[root@ecshost ~]# fdisk -l
Disk /dev/vda: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0008d73a

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048    41943039    20970496   83  Linux

Run the df -h command to check the disk partition size.

In this example, the /dev/vda1 partition size is 20 GiB.

[root@ecshost ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        20G  1.5G   18G   8% /
devtmpfs        7.8G     0  7.8G   0% /dev
tmpfs           7.8G     0  7.8G   0% /dev/shm
tmpfs           7.8G  344K  7.8G   1% /run
tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup
tmpfs           1.6G     0  1.6G   0% /run/user/0

Run the growpart<DeviceName><PartionNumber> command to use the growpart tool to resize the specified system disk and partition.
In this example, the first partition of the system disk is resized.
```
[root@ecshost ~]# growpart /dev/vda 1
CHANGED: partition=1 start=2048 old: size=41940992 end=41943040 new: size=209710462,end=209712510
```

Run the resize2fs <PartitionName> command to use the resize2fs tool to extend the file system.

In this example, the file system of the /dev/vda1 partition is extended.

[root@ecshost ~]# resize2fs /dev/vda1
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/vda1 is mounted on /; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 7
The filesystem on /dev/vda1 is now 26213807 blocks long.

Note If an XFS file system is used, run the xfs_growfs /dev/vda1 command.

Run the df -h command to check the size of the disk partition.

In this example, the /dev/vda1 partition size is 100 GiB, which means that the partition is resized.

[root@ecshost ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        99G  1.6G   93G   2% /
devtmpfs        7.8G     0  7.8G   0% /dev
tmpfs           7.8G     0  7.8G   0% /dev/shm
tmpfs           7.8G  500K  7.8G   1% /run
tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup
tmpfs           1.6G     0  1.6G   0% /run/user/0

Procedure for instances with kernels earlier than 3.6.0

This procedure uses an instance running CentOS 6 to describe how to resize a system disk partition.

Install the dracut-modules-growroot tool.
```
[root@ecshost ~]# yum install -y dracut-modules-growroot
```
If a package manager other than yum is used, change yum to the corresponding command.
Run the following command to overwrite the existing initramfs file.
```
[root@ecshost ~]# dracut -f
```

Run the fdisk -l command to check the current disk size.