This topic describes disk space-related issues that typically occur on Linux Elastic Compute Service (ECS) instances.
Issues
Take note of the following items:
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The following disk space-related issues typically occur on Linux ECS instances:
Disk space is used up
For information about how to troubleshoot this issue, see What do I do if disk space or inodes are used up on a Linux instance?
The amount of disk space in the df command output differs from that in the du command output
For information about how to troubleshoot this issue, see The results displayed when you run the df and du commands to view the disk are inconsistent.
Negative values are displayed in the df command output
Problem description
After you run the df -h command on a Linux instance to check disk usage, negative values are displayed in the command output. 
Cause
In Linux, a partition that accounts for 5% or more of space on a disk is reserved for the root user or other specific users. When the space of a reserved partition is occupied, a negative value is displayed for disk space.
Solution
Run the rm command to delete large files from disks to free up the space of reserved partitions that is occupied by the files. Then, run the df command to check disk usage again. You can find that no negative values are displayed in the df command output.