File System Management - Investigating High Disk Usage

Introduction:

Effective file system management is essential for maintaining a well-functioning and optimized server. However, incidents related to high disk usage can occur, leading to potential performance issues and system instability. In this blog post, we will explore how to investigate and address high disk usage issues using Linux commands such as watch, lsof, du, df, and ./script1.sh.

Step 1: Monitor Open Files

To investigate the cause of high disk usage, start by monitoring open files in the relevant directory. Use the watch command with the lsof utility to continuously check for open files. For example:

watch -n 5 "lsof | grep /data/file2" &

This will display a live view of processes that have the file "/data/file2" open, allowing you to identify any active processes that might be causing the high disk usage.

Step 2: Check Directory Size

Next, determine the size of the "/data" directory to see if it is contributing to the high disk usage. Use the du command with the -h option to display sizes in a human-readable format:

du -h /data

This command will show the size of each subdirectory and file within "/data", helping you identify any large files or directories that might be causing the issue.

Step 3: Check Overall Disk Usage

Now, check the overall disk usage on your system to determine if the high disk usage is localized or affecting the entire filesystem. Use the df command with the -hT options to view a summary of disk usage for all mounted filesystems:

df -hT

This will provide information about the total, used, and available space on each mounted filesystem, helping you identify if any other filesystems are experiencing high usage as well.

Step 4: Analyze Script and Tasks

If the investigations above do not pinpoint the cause of high disk usage, review any custom scripts or tasks running on the server. For example, check the contents of script1.sh to ensure that it is not generating excessive data or consuming disk space unexpectedly:

./script1.sh

Examine the script logic and contents to ensure it is functioning as intended and not causing unintended disk usage.

Conclusion:

High disk usage incidents require prompt investigation and careful analysis to identify and address the root cause. By using Linux commands like watch, lsof, du, df, and ./script1.sh, administrators can efficiently investigate and resolve high disk usage issues, ensuring a stable and optimized server environment.

Regularly monitor disk usage, investigate unexpected spikes, and optimize disk space usage to maintain a well-functioning and efficient system.