How to backup and restore Volumio SD card and shrink zero space.
Backup SD card with "dd":
sudo dd bs=4M if=/dev/sdX of=/path/to/your/backup.img status=progress
Backup SD card with "Disks in Ubuntu":
- Open Disks
- Create Disk Image...
- Enter a location where to save the image
Shrink image zero space and compress to gz:
pishrink -z backup.img backup_shrink.img-z- Compress image after shrinking with gzip
Decompress with gzip:
gzip -dk backup.img.gz-d- decompress-k- keep (don't delete) input files
Restore image to SD card with "dd":
sudo dd bs=4M if=/path/to/your/backup.img of=/dev/sdX status=progress
Restore image to SD card with "Disks in Ubuntu":
- Open Disks
- Restore Disk Image...
- Browse to the location of the image file
Resize partition to max size of SD card:
e2fsck -f /dev/sdc3resize2fs /dev/sdc3