50 lines
1.6 KiB
Bash
Executable File
50 lines
1.6 KiB
Bash
Executable File
#!/usr/bin/env bash
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# Refresh the SD card (mmcblk0p2) as a live boot-fallback clone of the
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# running root filesystem. Run manually after a push:
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# sudo ./failover/sync-sd-backup.sh
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#
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# EEPROM BOOT_ORDER falls back to the SD card if the primary boot disk
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# (NVMe) doesn't come up. /etc/fstab, /etc/machine-id, and /var/log are
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# excluded from the sync so the clone keeps its own partition identity
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# (PARTUUIDs differ per disk) and boot/journal history instead of
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# inheriting the source disk's — see failover/README or repo memory
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# "sd-fallback-fstab-clobber" for what breaks if those leak across.
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set -euo pipefail
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[ "$(id -u)" -eq 0 ] || { echo "Run as root (sudo)." >&2; exit 1; }
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SD_ROOT_PART=/dev/mmcblk0p2
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MOUNT_POINT=/mnt/sd-backup-root
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root_src=$(findmnt -no SOURCE /)
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if [ "$root_src" = "$SD_ROOT_PART" ]; then
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echo "Currently booted from $SD_ROOT_PART — refusing to sync SD onto itself." >&2
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exit 1
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fi
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mkdir -p "$MOUNT_POINT"
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mounted_here=0
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if ! mountpoint -q "$MOUNT_POINT"; then
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mount "$SD_ROOT_PART" "$MOUNT_POINT"
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mounted_here=1
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else
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mount -o remount,rw "$MOUNT_POINT"
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fi
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cleanup() {
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if [ "$mounted_here" -eq 1 ]; then
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umount "$MOUNT_POINT"
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fi
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}
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trap cleanup EXIT
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rsync -aHAX --numeric-ids --delete \
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--info=progress2 \
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--exclude=/proc/* --exclude=/sys/* --exclude=/dev/* --exclude=/run/* \
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--exclude=/tmp/* --exclude=/mnt/* --exclude=/media/* --exclude=/lost+found \
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--exclude=/boot/firmware/* --exclude=/swapfile \
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--exclude=/etc/fstab --exclude=/etc/machine-id --exclude=/var/log/* \
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--stats / "$MOUNT_POINT/"
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echo "SD backup ($SD_ROOT_PART) synced from $root_src."
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