RaspiBackup.sh

Script to backup a Raspberry Pi SDCARD to an imagefile. The resulting file can be installed to a sdcard. Refer to https://www.raspberrypi.org/documentation/installation/installing-images/README.md

Read this text to the end, before use!

This script creates system backup to an image file. It creates backups of the device where the system was booted. It does not matter if the system was started from an SD card or a SSD drive. The size of the image will be calculated as the used size of the / partition plus 256m for /boot plus 500mb reserve. This is not the size of the entire device, as 30 GB for a SSD drive where only 4 GB of root partition resides.

It is really helpful, if you run your system from a large partition residing on a SSD drive.

🛑 Using an imager all existing data on the target will be removed.

💡 If your destination contains other partitions you want to keep, do the following:

• restore to a SD card
• boot from this SD card
• mount your SSD boot partition and the SSD root partition
• copy / to the SSD root partition omitting /boot or /boot/firmware (depending on your Rsapian version) e.g. rsync -aEvx --del --exclude='/boot/**' / [mountdir of ssd root]
• copy the content of /boot or /boot/firmware to the SSD boot partition e.g. cp -a /boot/* [mountdir of ssd boot]
• get the PARTUUID of [mountdir of ssd boot] and [mountdir of ssd root]

  sudo bash
  BOOTDEV=$(findmnt  -c -n --uniq -o SOURCE [mountdir of ssd boot])
  ROOTDEV=$(findmnt  -c -n --uniq -o SOURCE [mountdir of ssd root])
  BootPARTUUID=$(lsblk -n -o PARTUUID "${BOOTDEV}")
  RootPARTUUID=$(lsblk -n -o PARTUUID "${ROOTDEV}")
  echo "Boot PARTUUID_:${BootPARTUUID}"
  echo "Root PARTUUID_:${RootPARTUUID}"
  

• check/change PARTUUID in [mountdir of ssd boot]/cmdline.txt to ${RootPARTUUID}
• check/change the PARTUUIDS of / and /boot in [mountdir of ssd root]/etc/fstab to ${RootPARTUUID} and ${BootPARTUUID}

Usage

• RaspiBackup.sh COMMAND OPTION sdimage

E.g.:

• RaspiBackup.sh start [-cslzdf] [-L logfile] sdimage
• RaspiBackup.sh mount [-c] sdimage [mountdir]
• RaspiBackup.sh umount sdimage [mountdir]
• RaspiBackup.sh gzip [-df] sdimage (deprecated)
• RaspiBackup.sh showdf sdimage
• RaspiBackup.sh resize [-s] size sdimage

Commands:

• start - starts complete backup of RPi's SD Card to 'sdimage'
• mount - mounts the 'sdimage' to 'mountdir' (default: /mnt/'sdimage'/)
• umount - unmounts the 'sdimage' from 'mountdir'
• gzip - compresses the 'sdimage' to 'sdimage'.gz (deprecated)
• showdf - Shows allocation of image
• resize - resize the image

Options:

• -c creates the SD Image if it does not exist
• -l writes rsync log to 'sdimage'-YYYYmmddHHMMSS.log
• -z compresses the SD Image (after backup) to 'sdimage'.gz (deprecated) use pishrink instead.
• -d deletes the SD Image after successful compression
• -f forces overwrite of 'sdimage'.gz if it exists
• -L logfile writes rsync log to 'logfile'
• -s define the size of the image file in M

Examples:

Start backup to backup.img, creating it if it does not exist. The size of the image corresponds to thje used size of the root partition, plus additional 256m for /boot and 500m reserve.

RaspiBackup.sh start -c /path/to/backup.img

Start backup to backup.img, creating it if it does not exist, limiting the size to 8000M. Keep in mind: you are responsible defineing a size large enough to hold all files to backup! There's no such thing as a size check.

RaspiBackup.sh start -s 8000 -c /path/to/backup.img

Refresh of backup.img. (only noncompressed images can be refreshed)

RaspiBackup.sh start /path/to/backup.img

Mount the RPi's Image in /mnt/backup.img:

RaspiBackup.sh mount /path/to/backup.img /mnt/backup.img

Unmount the Image from default mountdir (/mnt/backup.img/):

RaspiBackup.sh umount /path/to/backup.img

show allocation of Image:

RaspiBackup.sh showdf /path/to/backup.img

increase the size of the Image by 1000M:

RaspiBackup.sh resize  /path/to/backup.img

increase the size of the Image by a specific amount (here 2000M):

RaspiBackup.sh resize -s 2000  /path/to/backup.img

Note: Image compression is deprecated, a better alternative is to use filesystems that allow compressed folders (e.g. BTRFS)

⚡ Caveat:

This script takes a backup while the source partitions are mounted and in use. The resulting imagefile will be inconsistent!

To reduce inconsistencies, you need to terminate as many services as possible before you start backing up. You can put the system in rescue mode (be careful: new SSH connections are not possible in rescue mode), take the backup and put your system back in default mode.
A sample is given as WeeklyBackup.sh. WeeklyBackup.sh.

Recommendation:

Use a filesystem for the target that can handle snapshots (e.g. BTRFS). Creating a snapshot, before starting a backup, results in a space efficient versioning backup.