Linux Disk, Storage, and Filesystem Troubleshooting

Disk issues are common in Linux support. Applications may fail to write logs, databases may stop accepting data, deployments may fail, or users may see strange errors. Often the root cause is simple: the filesystem is full, inodes are exhausted, or the expected mount is missing.

The safest approach is to inspect first, understand what is consuming space, and then decide the right cleanup or escalation path.

Disk space versus inode usage

df -h shows storage space. df -i shows inode usage, which means how many file entries are available. A system can have free disk space but still fail if inodes are exhausted by too many small files.

Useful commands

• df -h checks filesystem space in readable units.
• df -i checks inode usage.
• du -sh /path/* finds large directories under a path.
• find /path -type f -size +500M finds large files.
• lsblk shows block devices and mount points.
• mount confirms what is currently mounted.

Support workflow

1. Check df -h and identify the affected filesystem.
2. Check df -i to rule out inode exhaustion.
3. Use du carefully to find where space is being consumed.
4. Check whether the expected mount exists before cleaning files.
5. Do not delete business or application data without approval.

Practical note

If logs are growing quickly, deleting one old file may not solve the incident. You should identify why logs are growing, whether log rotation is working, and whether the application is repeatedly failing.