When managing a Linux server, you may encounter a situation where the root filesystem runs out of space. In this guide, we will walk through how to expand a Linux filesystem, focusing on cases where the root partition is nearly full.
Step 1: Check Disk Usage
Before expanding your filesystem, it is important to assess the current disk space usage. Use the following command to check the disk usage:
df -H
Example output:
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 2.2G 2.0G 87M 96% /
In this case, the root (/
) partition is nearly full.
Step 2: Check Available Disk Space
To see if there is unallocated space on your disk, run:
lsblk
Example output:
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 10G 0 disk
├─sda1 8:1 0 2.1G 0 part /
Here, /dev/sda
is 10GB, but /dev/sda1
(the root partition) is only 2.1GB, meaning there is unallocated space available.
Step 3: Check Filesystem Type
Different filesystems require different commands to resize. Run the following command to determine the filesystem type:
df -T /
Example output:
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 ext4 2.2G 2.0G 87M 96% /
If the filesystem is ext4, use resize2fs
. If it were XFS, we would use xfs_growfs
.
Step 4: Expand the Partition
Since the root partition is actively in use, you need to modify it while the system is running. First, install the necessary tool if it’s not available:
apt update && apt install cloud-guest-utils -y
Then, expand the partition:
growpart /dev/sda 1
Verify the change with:
lsblk
Step 5: Resize the Filesystem
Now, resize the filesystem using the appropriate command:
If Using ext4:
resize2fs /dev/sda1
If Using XFS:
xfs_growfs /
(Note: The XFS command will only work if the filesystem is XFS.)
Step 6: Confirm the Expansion
Finally, check if the filesystem has been successfully resized:
df -H
The root partition should now have more space available.
Conclusion
Expanding a Linux filesystem is crucial when your root partition is running low on space. By following these steps, you can safely extend your partition and avoid system crashes due to insufficient disk space. If you encounter any issues, ensure your disk has unallocated space before resizing the filesystem.