create_zfs_dataset creates an empty snapshot, snapshot_zfs_datasets checks if...

create_zfs_datasets.sh

@@ -133,3 +133,6 @@ mkdir -p "$TOP_LEVEL_DATASET_MOUNTPOINT/logs/caddy"
 chown -R 1000:100 "$TOP_LEVEL_DATASET_MOUNTPOINT/logs"
 # 105:109 is postgres:postgres inside the container
 chown -R 105:109 "$TOP_LEVEL_DATASET_MOUNTPOINT/logs/postgresql" "$TOP_LEVEL_DATASET_MOUNTPOINT/logs/pgbadger"
+
+# Create a snapshot called 'empty'
+./snapshot_zfs_datasets.sh empty

snapshot_zfs_datasets.sh

@@ -134,6 +134,33 @@ fi
 
 echo "All datasets appear unmountable"
 
+if [ "$SNAPSHOT_NAME" != "empty" ]; then
+  if [ ! -e "${TOP_LEVEL_DATASET_MOUNTPOINT}/shared_memory/shared_memory.bin" ]; then
+    echo "Warning: No shared memory file found in the shared_memory directory"
+    exit 1
+  fi
+
+  last_shared_memory_write=$(stat -c %Y "${TOP_LEVEL_DATASET_MOUNTPOINT}/shared_memory/shared_memory.bin")
+  last_blockchain_write=$(find "${TOP_LEVEL_DATASET_MOUNTPOINT}/blockchain" -type f -printf '%T@\n' | sort -n | tail -1)
+
+  if [ -z "$last_blockchain_write" ]; then
+    echo "Warning: No files found in the blockchain directory"
+    exit 1
+  fi
+
+  time_diff=$((last_blockchain_write - last_shared_memory_write))
+
+  if [ $time_diff -gt 300 ] || [ $time_diff -lt -300 ]; then
+    echo "Warning: The shared_memory.bin file was not written to within 5 minutes of the last write to a file in the blockchain directory."
+    read -p "Do you want to continue? (y/n): " choice
+    case "$choice" in
+      y|Y ) echo "Continuing...";;
+      n|N ) echo "Aborting."; exit 1;;
+      * ) echo "Invalid input. Aborting."; exit 1;;
+    esac
+  fi
+fi
+
 if [ $PUBLIC_SNAPSHOT -eq 1 ]; then
   stdbuf -o0 echo ""
   stdbuf -o0 echo "Moving log files out of the dataset because this is a public snapshot... "