Hosting Operations
Read-onlySummarize Docker Disk Usage
The host disk is full and you need a safe storage summary before cleanup.
Command
docker system df -vBefore you run this
System impact: Read-only. Low when scoped to the shown target.
When not to use it: Do not treat reclaimable space as safe to delete until you verify ownership and backups.
Expected output
A Docker disk usage summary with reclaimable space estimates.
System impact
Read-only. Nothing changes. Docker reads storage accounting data.
Recovery / rollback: no state is changed.
When to use it
Use before cleanup decisions to understand whether images, containers, volumes, or build cache are responsible.
When not to use it
Do not treat reclaimable space as safe to delete until you verify ownership and backups.
Volume warning
Reclaimable image or cache space is different from volume data. Treat volumes as persistent until mapped to containers and backups.
docker system df -vdocker ps -a --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}'
next steps
Related commands
Check Bytes and Inodes Before Cleanup
No space left can mean full bytes, full inodes, or both.
df -h /var && df -ih /var
Check Inodes When Disk Space Looks Fine
Sometimes the disk has free bytes but still cannot create files.
df -ih
Check Container Health Status
Docker may say a container is running while its health check says otherwise.
docker inspect --format '{{.Name}} health={{if .State.Health}}{{.State.Health.Status}}{{else}}none{{end}} status={{.State.Status}}' web
Show Containers in a Clean Triage Table
Turn noisy docker ps output into the few fields operators scan first.
docker ps -a --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}\t{{.Ports}}'
Snapshot Container CPU and Memory
Get Docker resource usage once, without leaving a live dashboard running.
docker stats --no-stream --format 'table {{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.NetIO}}\t{{.BlockIO}}'
next diagnostic step
Where to go from this command
- Docker disk full hub Use when Docker storage is filling the host filesystem.
Study mapping
Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.
Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.