Storage Management

Your PCS has a finite amount of disk space. As you install apps and accumulate data, managing storage becomes important. This guide covers how to monitor, optimize, and expand your storage.

Monitoring Disk Usage

From the Admin Panel

1. Go to Admin Panel → Resources → Disk tab.
2. You'll see:
   • Total disk space and used space
   • Usage percentage — keep this below 85% for optimal performance
   • Disk benchmark results (if you've run one)

From CasaOS

The CasaOS dashboard shows a Disk widget at the top with a quick overview of used vs total space.

From Terminal

For more detail, connect via Admin Panel → Terminal:

# Overall disk usage
df -h /

# Size of each app's data
du -sh /DATA/AppData/*/

# Top 10 largest directories
du -sh /DATA/AppData/*/ | sort -rh | head -10

# Size of Docker images
docker system df

What Uses Disk Space

Here's where your disk space typically goes:

Category	Location	Typical Size
App data	/DATA/AppData/<app>/	Varies greatly
Docker images	Docker storage	100MB–2GB per app
Backups	/DATA/AppData/ (zip files)	Same as app data
System	/ (root filesystem)	5–10 GB
Docker build cache	Docker storage	Can grow over time

Space-Hungry Apps

Some apps use significantly more disk space than others:

• Immich — Photo and video libraries can be very large (50GB–1TB+)
• Jellyfin — Media libraries (movies, TV shows) are typically the largest
• Nextcloud — Depends on how much you sync, can grow rapidly
• Databases — Apps with databases (Docmost, Vaultwarden) are usually small

Cleaning Up Disk Space

1. Remove Old Backups

Backups can accumulate and consume significant space.

From Admin Panel:

1. Go to Admin Panel → Apps.
2. Check the Backups count for each app.
3. Delete old backups you no longer need, keeping the 2–3 most recent.

From Terminal:

# Find all backup files
find /DATA/AppData/ -name "*.tar.gz" -o -name "*backup*.zip" | sort

# Check total backup size
find /DATA/AppData/ -name "*backup*" -exec du -sh {} + | sort -rh

# Delete backups older than 30 days
find /DATA/AppData/ -name "*backup*" -mtime +30 -delete

2. Clean Docker Resources

Docker can accumulate unused images, containers, and volumes.

# See how much space Docker is using
docker system df

# Remove unused containers, images, and build cache
docker system prune

# More aggressive: also remove unused volumes (WARNING: may delete data)
docker system prune --volumes

warning

Be careful with docker system prune --volumes — it removes unused volumes which might contain app data. Only use this if you're sure no important data is in orphaned volumes.

3. Clean App-Specific Data

Some apps have their own cleanup options:

• Immich — Remove duplicate photos, empty trash
• Jellyfin — Clear cache from Jellyfin settings
• Nextcloud — Empty trash, clear preview cache

4. Uninstall Unused Apps

If you have apps you no longer use:

1. Create a backup first from Admin Panel → Apps (in case you want them later).
2. Uninstall from CasaOS — right-click the app and choose Uninstall.
3. Choose Delete data if you're sure you won't need it again.

Disk Health

Running a Disk Benchmark

1. Go to Admin Panel → Resources → Disk tab.
2. Click Run disk benchmark.
3. Compare results with expected values for your disk type:

Disk Type	Expected Read Speed	Expected Write Speed
HDD	100–200 MB/s	80–150 MB/s
SATA SSD	400–550 MB/s	350–500 MB/s
NVMe SSD	1000–3500 MB/s	800–3000 MB/s

Significantly lower results may indicate a failing disk.

Signs of Disk Problems

• Sudden slow performance
• Apps crashing or failing to start
• Error messages about I/O errors in app logs
• Benchmark results much lower than expected

If you suspect disk issues, create backups immediately and consider migrating to a new PCS.

Expanding Storage

External USB Storage

You can attach external USB drives to your PCS for additional storage:

1. Connect the USB drive to the PCS.
2. From Terminal, find the drive:

   lsblk

3. Mount the drive:

   sudo mkdir -p /mnt/external
   sudo mount /dev/sdb1 /mnt/external

4. To make it permanent, add it to /etc/fstab.

Using External Storage for Media

For media-heavy apps like Jellyfin or Immich, you can store media on the external drive and configure the app to read from that location.

Storage Best Practices

• Monitor regularly — Check disk usage monthly from the admin panel
• Keep backups lean — Maintain only 2–3 recent backups per app
• Clean Docker periodically — Run docker system prune monthly
• Set up alerts — Use Uptime Kuma to monitor disk usage percentage
• Plan for growth — If you're above 70% usage, start planning for more space
• Keep 15% free — Performance degrades significantly when disks are over 85% full