Complete backup of the Raspberry Pi microSD card – indi-allsky backup

indi-allsky on a Raspberry Pi system regularly writes data (logs, databases, images, videos).
microSD cards are only designed for this to a limited extent and can fail without warning in the worst case.

A 1:1 backup of the entire SD card is possible in an emergency:

Insert a new microSD card
Restore the backup
System starts exactly in the previous state

What is backed up in this guide?

The procedure described here creates a complete, bootable image of the SD card including:

Bootloader
partition table
operating system
Installed software
configurations
Data (e.g. indi-allsky, images, videos)

This is not a file backup, but a block-level image.

Requirements

Raspberry Pi is accessible via network

SSH access available

Backup is started from another computer (Linux, macOS, Windows with WSL)

Sufficient free disk space on the backup computer

Step 1: Check SSH access to the Raspberry Pi

From the backup computer:

 ssh pi@<IP-ADRESS-DES-PI>

If the login works, you can start the backup.

Step 2: Identify the SD card on the Raspberry Pi

On the Raspberry Pi:

 lsblk

Typical output:

 mmcblk0 59.5G 
├─mmcblk0p1 256M 
└─mmcblk0p2 59.2G

The entire device is important:

 /dev/mmcblk0

Do not back up individual partitions.

Step 3: Stop writing services briefly (recommended)

If applications are running that are actively writing (e.g. indi-allsky, databases, camera software), these should be stopped briefly.

Example for indi-allsky (classic installation):

 systemctl --user stop indi-allsky.service 2>/dev/null || true
systemctl --user stop gunicorn-indi-allsky.socket 2>/dev/null || true
systemctl --user stop gunicorn-indi-allsky.service 2>/dev/null || true
systemctl --user stop indiserver.service 2>/dev/null || true
systemctl --user stop indi-allsky.timer 2>/dev/null || true
systemctl --user stop indiserver.timer 2>/dev/null || true

This ensures a consistent backup.

Step 4: Create a complete backup via SSH

The actual backup command is executed on the backup computer:

 ssh pi@<IP-ADRESS-DES-PI> \ 
"sudo dd if=/dev/mmcblk0 bs=4M status=progress" \ 
| gzip > raspberry-backup-$(date +%F).img.gz

What happens in the process:

dd reads the complete SD card raw
Data is transferred via SSH
Backup is stored locally compressed
Empty storage space is greatly reduced

Depending on the card size, the process takes a few minutes.

Important: A complete image is created – it is not possible to skip individual directories, for example.

Step 5: Restart services

Once the backup is complete, the previously stopped services can be restarted
or alternatively the Raspberry Pi can be rebooted:

 sudo reboot

Where is the backup saved?

The backup is saved on the computer on which the command was executed, not on the Raspberry Pi.

The backup is located in the current working directory, e.g:

 ~/raspberry-backup-2025-01-07.img.gz

Restoration in an emergency

If the SD card is defective:

Insert a new microSD card into the backup computer
Restore the backup:

 gzip -dc raspberry-backup-2025-01-07.img.gz \ 
| sudo dd of=/dev/mmcblk0 bs=4M status=progress sync

Insert the microSD card into the Raspberry Pi
Start

The system then runs exactly as it did at the time of the backup

Avoid typical errors

Do not save a backup on the same microSD card
Do not just back up individual partitions
Always check the target device carefully when restoring
Restore the backup at least once as a test