Server low on disk space: what to check before deleting files

What to do when a server runs out of space?

First you must identify what volume is growing, since when, and what service writes to it. Deleting random files can damage applications or delete evidence. It is best to only release known content, correct the cause, and set up alerts before critical space runs out again.

Risks to review

• Delete databases, active logs, snapshots, or files needed for recovery.
• Expand the disk without resolving a process that grows abnormally.
• Stop critical services without knowing dependencies.
• Copy sensitive data to unprotected temporary locations.

Safe recommendations

1. Confirm volume, free percentage, trend and affected service.
2. Identify large folders with supported tools and appropriate permissions.
3. Review logs, temps, updates, dumps, databases, and backup jobs.
4. Only release documented files with authorization from the service owner.
5. If you expand capacity, validate file system, backup and change window.
6. Set alerts by percentage, absolute space and growth rate.

When to seek specialized help

• The volume contains databases, virtual machines, or domain services.
• The server is unstable or the available space continues to drop rapidly.
• There is no recent backup nor is the owner of the files known.