Managing ServiceNow Storage Effectively: Tips, Pitfalls, and AI Opportunities

 

🧠 Introduction

As organizations grow, so does their ServiceNow data. From audit logs to attachments and historical records, an unmanaged instance can quickly exceed storage limits — leading to performance degradation, license breaches, or even functionality risks.

In this article, we explore practical and strategic ways to manage your ServiceNow storage footprint, including smart automation like auto-flush rules and how AI can support proactive cleanup and decision-making.

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🧰 1. Understand What’s Consuming Space

Start by identifying top storage consumers:

• Navigate to System Diagnostics → Tables to view table sizes.

• Focus on heavy tables like sys_audit, sys_email, sys_attachment, task, and cmdb_ci.

🧾 Script: List tables over 1GB

javascript

var gr = new GlideTableSizeUtil();
var tables = gr.getAllTableSizes();
while (tables.next()) {
  if (tables.size_bytes > 1073741824) {
    gs.print(tables.name + " — " + (tables.size_bytes / 1073741824).toFixed(2) + " GB");
  }
}

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🔄 2. Use Auto-Flush for Log and System Tables

For fast-growing system tables, auto-flush rules are the recommended method to manage data safely and efficiently.

📍 Examples of flushable tables:

• syslog_transaction

• syslog

• sys_email

• sys_rollback_sequence

• sys_audit_delete

• ecc_queue

🛠️ Configure via:

System Definition → Auto Flush Rules

🔧 Example: Auto-flush syslog_transaction older than 30 days:

Table: syslog_transaction  
Condition: sys_created_on < javascript:gs.daysAgo(30)  
Batch Size: 500

✅ Auto-flush avoids scripting risks and runs in controlled background processes.

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🧾 3. Use Retention Policies for Business Data

For structured business records (like incidents or change requests), use:

• Auto Archive Rules for historical visibility

• Auto Delete Rules for permanent cleanup when archive isn’t required

• Data Retention Policies aligned with legal/compliance frameworks

Avoid deleting directly via script unless absolutely necessary.

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🤖 4. AI-Driven Optimization (Emerging Practice)

AI models can enhance storage strategies by:

• Recommending purge targets based on usage frequency

• Highlighting duplicate or redundant attachments

• Analyzing long-running jobs for inefficiencies

🧾 Script: Identify long-duration scheduled jobs

javascript

var jobLog = new GlideAggregate('sys_trigger');
jobLog.addAggregate('AVG', 'duration');
jobLog.groupBy('name');
jobLog.orderByAggregate('AVG', 'duration');
jobLog.query();
while (jobLog.next()) {
  gs.print(jobLog.name + " → Avg Duration: " + jobLog.getAggregate('AVG', 'duration') + " ms");
}

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💡 5. Common Pitfalls to Avoid

• Overusing scripting to delete data: Prefer system-supported methods like auto-flush or retention rules.

• Archiving ≠ deleting: Archives still consume space, though less than active records.

• Uncoordinated full data pulls from PROD can lead to slowness, API throttling, or job failures.

• Neglecting email and attachment tables, which silently grow large.

🧾 Script: Find attachments >50MB, older than 1 year

javascript

var attach = new GlideRecord('sys_attachment');
attach.addEncodedQuery('size_bytes>52428800^sys_created_onRELATIVELE@year@ago@1');
attach.query();
while (attach.next()) {
  gs.print(attach.file_name + " — " + (attach.size_bytes / 1048576).toFixed(2) + " MB");
}

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🔐 6. Enforce Limits for Integrations and APIs

• Use properties like glide.rest.query.max_records to limit API responses.

• Restrict external integrations from triggering large table queries.

• Rate-limit ETL tools or enforce best practices on full/delta pulls.

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🧭 7. Collaborate with Data Consumers

• Communicate with data warehouse/ETL teams using Table API.

• Insist that full-load testing happens in non-prod, never directly on production.

• Prevent SQL teams from running unattended test queries against live instances.

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📊 System Tables to Auto-Flush or Archive

Table Name	Reason for Growth	Recommended Action
sys_audit	Field change logs	Auto-archive or delete
sys_email	All email activity	Auto-flush after retention
syslog_transaction	Transaction logs	Auto-flush older entries
sys_rollback_sequence	Workflow rollback data	Auto-flush
sys_attachment_doc	File storage	Identify & purge large/old

📌 Conclusion

Managing storage in ServiceNow is about more than just saving disk space. It’s a proactive approach to maintaining performance, cost efficiency, and platform health. With the right mix of auto-flush, retention rules, and even AI-enhanced analysis, you can keep your instance lean and compliant — while avoiding manual, error-prone deletion methods.