Create rm-db-from-journal.sh

Author: Hutch-45D

rm-db-from-journal.sh

@@ -0,0 +1,113 @@
+#!//bin/bash
+# Nov 2025
+# 45Drives
+# Matthew Hutchinson <mhutchinson@45drives.com>
+
+set -euo pipefail
+
+need() { command -v "$1" >/dev/null 2>&1 || { echo "Missing $1"; exit 1; }; }
+need ceph
+need ceph-volume
+need lvs
+need readlink
+need systemctl
+need awk
+
+stop_osd() { systemctl stop "ceph-osd@$1" 2>/dev/null || true; }
+start_osd() { systemctl start "ceph-osd@$1" 2>/dev/null || true; }
+
+to_vg_lv() {
+  local dev="$1"
+  if [[ "$dev" =~ ^/dev/[^/]+/[^/]+$ ]]; then
+    awk -F'/' '{print $3"/"$4}' <<<"$dev"
+    return 0
+  fi
+  local vg lv
+  read -r vg lv < <(lvs --noheadings -o vg_name,lv_name "$dev" 2>/dev/null | awk '{print $1, $2}')
+  if [[ -n "${vg:-}" && -n "${lv:-}" ]]; then
+    printf "%s/%s\n" "$vg" "$lv"
+    return 0
+  fi
+  return 1
+}
+
+mapfile -t DB_LINKS < <(ls /var/lib/ceph/osd/ceph-*/block.db 2>/dev/null | while read -r p; do [[ -L "$p" ]] && echo "$p"; done)
+
+if [[ ${#DB_LINKS[@]} -eq 0 ]]; then
+  echo "No OSDs on this host have a separate DB. Nothing to do."
+  exit 0
+fi
+
+OSD_IDS=()
+for link in "${DB_LINKS[@]}"; do
+  osd_id="$(basename "$(dirname "$link")" | cut -d- -f2)"
+  OSD_IDS+=("$osd_id")
+done
+
+echo "OSDs to migrate on this host:"
+printf "%s\n" "${OSD_IDS[@]}"
+
+echo
+read -rp "Continue and migrate all of the above OSDs now? [y/N] " go
+[[ "$go" =~ ^[Yy]$ ]] || { echo "Aborted"; exit 0; }
+
+echo
+echo "Setting noout for this host"
+ceph osd set noout || true
+cleanup() { echo; echo "Clearing noout"; ceph osd unset noout || true; }
+trap cleanup EXIT
+
+DB_LVS_TO_REMOVE=()
+
+for osd_id in "${OSD_IDS[@]}"; do
+  osd_dir="/var/lib/ceph/osd/ceph-$osd_id"
+  [[ -d "$osd_dir" ]] || { echo "Skipping OSD $osd_id (no directory)"; continue; }
+
+  fsid="$(cat "$osd_dir/fsid" 2>/dev/null || true)"
+  block_link="$(readlink "$osd_dir/block" || true)"
+  block_real="$(readlink -f "$osd_dir/block" || true)"
+  db_lv_link="$(readlink "$osd_dir/block.db" || true)"
+
+  if [[ -z "$fsid" || -z "$db_lv_link" ]]; then
+    echo "Skipping OSD $osd_id (missing fsid or block.db)"
+    continue
+  fi
+
+  target=""
+  if target="$(to_vg_lv "$block_link")"; then :; elif target="$(to_vg_lv "$block_real")"; then :; else
+    echo "Skipping OSD $osd_id (target vg/lv not found)"
+    continue
+  fi
+
+  echo
+  echo "Migrating OSD $osd_id to $target"
+
+  stop_osd "$osd_id"
+  ceph-volume lvm migrate --osd-id "$osd_id" --osd-fsid "$fsid" --from db wal --target "$target"
+  start_osd "$osd_id"
+
+  DB_LVS_TO_REMOVE+=("$db_lv_link")
+done
+
+echo
+echo "All migrations complete."
+
+if (( ${#DB_LVS_TO_REMOVE[@]} > 0 )); then
+  echo
+  read -rp "Do you want to remove the old DB LVs to reclaim space? [y/N] " rmdb
+  if [[ "$rmdb" =~ ^[Yy]$ ]]; then
+    for p in "${DB_LVS_TO_REMOVE[@]}"; do
+      echo "Removing $p"
+      lvremove -y "$p" || echo "lvremove failed for $p"
+    done
+  else
+    echo
+    echo "You chose to keep the old DB LVs. You can remove them later using:"
+    for p in "${DB_LVS_TO_REMOVE[@]}"; do
+      echo "  lvremove -y $p"
+    done
+  fi
+fi
+
+echo
+echo "Done."