first commit

2026-09-01 22:28:25 +03:00
commit 2ce4afdfdd
2 changed files with 256 additions and 0 deletions
@@ -0,0 +1,134 @@
+#!/usr/bin/env bash
+# Snapshot ZFS filesystems and stream each snapshot to a remote ZFS host.
+
+set -Eeuo pipefail
+
+usage() {
+    cat <<'EOF'
+Usage: zfs-move-over-ssh.sh [options] SOURCE_ROOT REMOTE_HOST DESTINATION_ROOT
+
+Create one snapshot for every filesystem under SOURCE_ROOT and send each one
+over SSH. Filesystems retain their relative paths below DESTINATION_ROOT.
+
+Arguments:
+  SOURCE_ROOT       Source ZFS filesystem, for example: tank/data
+  REMOTE_HOST       SSH host, optionally user@host
+  DESTINATION_ROOT  Existing or new destination ZFS filesystem, for example: backup/data
+
+Options:
+  -n, --dry-run              Print the ZFS and SSH commands without running them.
+  -i, --identity-file FILE   SSH private key to use.
+  -p, --ssh-port PORT        SSH port to use.
+  --destroy-source-snapshots Destroy each local migration snapshot after its successful receive.
+  -h, --help                 Show this help.
+
+The remote SSH account must be able to run `sudo -n zfs receive` without a
+password prompt. This script does not destroy source filesystems or data.
+EOF
+}
+
+die() {
+    printf 'Error: %s\n' "$*" >&2
+    exit 1
+}
+
+DRY_RUN=false
+DESTROY_SOURCE_SNAPSHOTS=false
+SSH_OPTIONS=()
+
+while (($#)); do
+    case "$1" in
+        -n|--dry-run)
+            DRY_RUN=true
+            ;;
+        -i|--identity-file)
+            (($# >= 2)) || die "$1 requires a file path"
+            SSH_OPTIONS+=(-i "$2")
+            shift
+            ;;
+        -p|--ssh-port)
+            (($# >= 2)) || die "$1 requires a port"
+            SSH_OPTIONS+=(-p "$2")
+            shift
+            ;;
+        --destroy-source-snapshots)
+            DESTROY_SOURCE_SNAPSHOTS=true
+            ;;
+        -h|--help)
+            usage
+            exit 0
+            ;;
+        --)
+            shift
+            break
+            ;;
+        -*)
+            die "unknown option: $1"
+            ;;
+        *)
+            break
+            ;;
+    esac
+    shift
+done
+
+(($# == 3)) || {
+    usage >&2
+    exit 2
+}
+
+SOURCE_ROOT="$1"
+REMOTE_HOST="$2"
+DESTINATION_ROOT="${3%/}"
+SNAPSHOT_NAME="move-$(date +%Y%m%d-%H%M%S)"
+
+command -v zfs >/dev/null || die "zfs command was not found"
+command -v ssh >/dev/null || die "ssh command was not found"
+zfs list -H -o name -t filesystem "$SOURCE_ROOT" >/dev/null || die "source filesystem does not exist: $SOURCE_ROOT"
+
+if ! $DRY_RUN; then
+    ssh "${SSH_OPTIONS[@]}" "$REMOTE_HOST" 'sudo -n zfs list -H -o name -t filesystem >/dev/null' \
+        || die "cannot run 'sudo -n zfs' on $REMOTE_HOST"
+fi
+
+map_destination() {
+    local filesystem="$1"
+    local relative_path="${filesystem#"$SOURCE_ROOT"}"
+    printf '%s%s\n' "$DESTINATION_ROOT" "$relative_path"
+}
+
+run() {
+    if $DRY_RUN; then
+        printf '+' >&2
+        printf ' %q' "$@" >&2
+        printf '\n' >&2
+    else
+        "$@"
+    fi
+}
+
+mapfile -t FILESYSTEMS < <(zfs list -H -o name -t filesystem -r "$SOURCE_ROOT")
+((${#FILESYSTEMS[@]} > 0)) || die "no filesystems found below $SOURCE_ROOT"
+
+printf 'Migration snapshot: %s\n' "$SNAPSHOT_NAME"
+for filesystem in "${FILESYSTEMS[@]}"; do
+    destination="$(map_destination "$filesystem")"
+    snapshot="${filesystem}@${SNAPSHOT_NAME}"
+
+    printf 'Transferring %s to %s:%s\n' "$filesystem" "$REMOTE_HOST" "$destination"
+    run zfs snapshot "$snapshot"
+
+    if $DRY_RUN; then
+        printf '+ zfs send -p %q | ssh' "$snapshot" >&2
+        printf ' %q' "${SSH_OPTIONS[@]}" "$REMOTE_HOST" "sudo -n zfs receive -uF '$destination'" >&2
+        printf '\n' >&2
+    else
+        zfs send -p "$snapshot" | ssh "${SSH_OPTIONS[@]}" "$REMOTE_HOST" "sudo -n zfs receive -uF '$destination'"
+    fi
+
+    if $DESTROY_SOURCE_SNAPSHOTS; then
+        run zfs destroy "$snapshot"
+    fi
+done
+
+printf 'Completed. Local source filesystems were not destroyed.\n'