Add attachment size audit script for ServiceNow

This script analyzes attachment storage in ServiceNow, identifying the largest attachments and their respective tables. It provides a read-only audit report to help manage storage usage.

Author: NowSharif

Server-Side Components/Background Scripts/Attachment Size Audit/attachmentSizeAudit.js

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+// Background Script: Attachment Size Audit
+// Purpose: Analyzes your ServiceNow instance's attachment storage to identify which tables and individual files consume the most space. 
+//Helps you understand storage usage patterns, locate oversized files, and plan cleanup or archival strategies. 
+//Provides a read-only audit report without modifying any data.
+//
+// Author: Masthan Sharif Shaik
+// Date: October 2025
+// Tested on: Zurich, Yokohama
+//
+// IMPORTANT: Test in non-production environment first
+
+(function attachmentSizeAudit() {
+
+    // ================= CONFIGURATION =================
+    var TOP_N_ATTACHMENTS = 25;        // Number of largest attachments to list
+    var MIN_SIZE_MB = 5;              // Only list attachments larger than this (MB)
+    var USE_COMPRESSED_SIZE = true;   // true = use size_compressed, false = use size_bytes
+    // =================================================
+
+    var sizeField = USE_COMPRESSED_SIZE ? "size_compressed" : "size_bytes";
+    var totalSizeBytes = 0;
+
+    gs.info("=== Attachment Size Audit Started ===");
+    gs.info("Using size field: " + sizeField.toUpperCase());
+
+    // ----------------- TOTAL SIZE --------------------
+    var totalAgg = new GlideAggregate("sys_attachment");
+    totalAgg.addAggregate("SUM", sizeField);
+    totalAgg.query();
+    if (totalAgg.next()) {
+        totalSizeBytes = totalAgg.getAggregate("SUM", sizeField);
+    }
+
+    gs.info("Total Attachment Storage: " +
+        formatBytes(totalSizeBytes));
+
+    // ------------- SIZE PER TABLE (AGGREGATED) --------------
+    gs.info("\n=== Storage Usage by Table (Descending) ===");
+
+    var tableAgg = new GlideAggregate("sys_attachment");
+    tableAgg.groupBy("table_name");
+    tableAgg.addAggregate("SUM", sizeField);
+    tableAgg.orderByAggregate("SUM", sizeField);
+    tableAgg.query();
+
+    while (tableAgg.next()) {
+        var table = tableAgg.getValue("table_name") || "<no table>";
+        var tableSize = tableAgg.getAggregate("SUM", sizeField);
+        gs.info(table.padEnd(40) + " : " + formatBytes(tableSize));
+    }
+
+    // --------------- TOP N BIGGEST ATTACHMENTS ---------------
+    gs.info("\n=== Top " + TOP_N_ATTACHMENTS + " Largest Attachments (>" + MIN_SIZE_MB + " MB) ===");
+
+    var attGR = new GlideRecord("sys_attachment");
+    attGR.addQuery(sizeField, ">", MIN_SIZE_MB * 1024 * 1024); 
+    attGR.orderByDesc(sizeField);
+    attGR.setLimit(TOP_N_ATTACHMENTS);
+    attGR.query();
+
+    while (attGR.next()) {
+        gs.info(
+            "[ " + formatBytes(attGR[sizeField]) + " ] " +
+            attGR.getValue("file_name") +
+            "  |  Table: " + attGR.getValue("table_name") +
+            "  |  Record: " + attGR.getValue("table_sys_id")
+        );
+    }
+
+    gs.info("\n=== Attachment Size Audit Complete ===");
+
+    // ------------- FORMATTER ----------------
+    function formatBytes(bytes) {
+        bytes = parseInt(bytes, 10) || 0;
+        if (bytes < 1024) return bytes + " B";
+        var i = Math.floor(Math.log(bytes) / Math.log(1024));
+        var sizes = ["B", "KB", "MB", "GB", "TB"];
+        var value = (bytes / Math.pow(1024, i)).toFixed(2);
+        return value + " " + sizes[i];
+    }
+
+})();