The target for the device is a low-power daily backup device that is robust enough to survive electrical blackouts and simple enough so that it can be duplicated for redundancy when needed.

• Read more about project background

Workflow

1. Wake up from suspend
2. Update e-ink display with message backup started + TIMESTAMP
3. Send heartbeat information to a remote server
4. Check that hardware is OK
5. RSYNC databases
6. RSYNC images
7. BACKUP Github repositories
8. Mount storage disk as read-only
9. Check using checksums that data was copied correctly
10. Update e-ink display with message backup was successfully finished + TIMESTAMP
11. Suspend for 24h and goto #1

Hardware

• Odroid M1 8GB (documentation: Odroid wiki)

• KKSB Odroid M1 Case

• KKSB 12mm Push Button Momentary Power Switch

• 12V/2A power supply EU plug

• CR 2032 RTC Battery

• 128GB eMMC Linux Module for Odroid M1 (boot & root drive)

• Odroid M1 SATA Mount and Cable Kit (documentation: Odroid wiki)

• Samsung PM897 2.5" SSD 3.84TB (storage drive)

• Badger 2040 (eink display)

• USB-A (Male) to USB-C Cable

• surge protector (?)

Install notes

• m.2 screw is using very small phillips screwdriver head
• eMMC card needs to be installed before board is installed to KKSB case as there is no room for fingers next to eMMC slot when it is in place
• Odroid M1 SATA Mount and Cable Kit screws are too long for attaching SSD:st to plate with some drives and additional screws are needed. For example Samsung PM897 screwholes are shorter than screws.

Power consumption notes

• Board with default OS (emmc with Ubuntu 20.04 ) average power consumption was ~3.5W (2.1.2022)
• Board with Ubuntu 22.04 via Petiboot (emmc, commandline only) average power consumption was ~4W (2.1.2022)
• Board with Debian bullseye install via Petiboot (emmc+Samsung 970 EVO Nvme) 8.4W max (4.1.2022)
• Board with Debian bullseye installed via Petiboot (emmc+Samsung PM897 2.5" SSD ) 4.7W max (21.1.2022)
• Board with Ubuntu 22.04 via Petiboot (emmc+Samsung PM897, commandline only) average power consumption was 5.7W (21.1.2022)
• Board with Debian GNU/Linux 11 (bullseye) (emmc+Samsung PM897 2.5" SATA+ 970 EVO Nvme + Badger eink) 4.86 W idle (20.10.2024)
• Board with Debian GNU/Linux 12 (bookworm) (emmc+Intel 1600x 118GB nvme) idle: 5.3W, load 8W (20.10.2024)
• Board with Debian GNU/Linux 12 (bookworm) (emmc+Intel 1600x 118GB nvme + PM897 SATA) idle: 6.5W (20.10.2024)
• Board with Ubuntu 24.04.1 LTS (emmc+Intel 1600x 118GB nvme + PM897 SATA) idle: 6.53 W, with HDMI: 6.96W (20.10.2024)
• Board with Debian GNU/Linux 12 (emmc+ WD Black SN850X nvme + PM897 SATA) idle: 6.43W, with HDMI: 7W (21.10.2024)

Operating system

• Debian 11 (installable via Petiboot netboot installer)

Alternatives

• Odroid default OS Ubuntu 20.04 : Ubuntu Kernel 4.19
• Armbian stable 22.11 with 6.1.y - (Odroid forum) (uses mainline kernel, doesn't support emmc?)
• Ubuntu 22.04 with 5.18 kernel (installable via Petiboot netboot installer)

OS Notes

Data drive Filesystem options

• Ext4 + md5sums for detecting bitrot + rsync --backup + optionally par2 data for recovering data
  • simple in filesystem level, but complex to implement scripting
• Ext4 + FS-PARITY for detecting bitrot + rsync --backup
  • works only for read only files, doesn't allow updating image files
• Zfs + snapshots + optionally two data copies for self-healing
  • Stable and well working, Incompatible licence with Linux kernel, doesn't work with Petiboot installations (requires Armbian to work out-of-the-box)
• Btrfs + snapshots + optionally two data copies for self-healing
  • Unstable reputation on unexpected KERNEL HALTS or powerloss
• Bcachefs
  • Beta and is not mainlined. Requires 6.2 kernel ( = Armbian) . Supports snapshots and checksumming and erasure coding.

Eink display

Badger 2040 with mpremote

sudo apt-get install python3-venv
source venv/bin/activate
pip install mpremote
mpremote exec "import badger2040; badger=badger2040.Badger2040();badger.pen(0);badger.text('Testing ...', 20,20);badger.update()"

Example boot status script

• badger.sh

Information in the display

On boot

• Date/time
• Local IP address
• Internet access state (OK/FAIL)
• Ssh server state (OK/FAIL)
• State: "START

On failure

• Date/time
• Local IP address
• Internet access state (OK/FAIL)
• Ssh server state (OK/FAIL)
• State: "FAILED (NUMBER)"

On backup finished

• Date/time
• Local IP address
• State: "BACKUP READY, SLEEPING..."

GPG Keys

• https://www.jwillikers.com/backup-and-restore-a-gpg-key

encrypt

cat file.gz | gpg --encrypt --batch --cipher-algo AES256 --compress-algo none -r b763e320fe05cc67744d8353d88eb927 -o file.gz.enc --trusted-key b763e320fe05cc67744d8353d88eb927 
gpg --output private.pgp --armor --export-secret-key b763e320fe05cc67744d8353d88eb927

On target machine

restore

scp username@source.org:/home/backup/private.pgp /home/restore/private.gpg
scp username@source.org:/home/backup/file.gz.enc /home/restore/file.gz.enc

gpg -o private.gpg --export-options backup --export-secret-keys
gpg --decrypt file.gz.enc |gzip -t

Flowchart