Mainframe Blog

Broadcom’s Virtual Storage Adapter: A Breakthrough in Mainframe Storage Efficiency

Written by Perry Jones | Aug 14, 2025 3:26:25 PM

Broadcom has delivered a first in mainframe storage with the Virtual Storage Adapter (VSA) enhancement to CA 1™ Flexible Storage™. This new feature lets you have your cake and eat it too – achieve high-performance virtual tape storage without the traditionally high costs of DASD and mainframe CPU cycles. 

The Storage Conundrum: Performance vs. Cost 

Historically, replacing directly connected Virtual Tape Library (VTL) hardware with virtual solutions on IBM Z has hit two major roadblocks: 

  1. Storage Requirements 
    Without a VTL appliance, data must be written to mainframe DASD, an extremely fast, but very expensive storage option typically reserved for database and application workloads demanding millisecond latency. 
  2. Processing Costs 
    VTLs offload processing from the mainframe. When replaced with software-based virtual tape, additional processing requirements can increase general-purpose mainframe CPU usage. This drives up Monthly License Charges (MLC) due to increased utilization, which is measured based on a four-hour rolling average. That means every workload spike hits your bottom line. 

Often, these challenges have made virtual tape storage solutions more costly and less attractive compared to purpose-built hardware-based VTLs. 

Upon customer request, Broadcom engineered a solution to eliminate both pain points, leveraging advances in hardware, z/OS, and hybrid cloud architecture. 

The result is Virtual Storage Adapter (VSA), a powerful new capability that: 

  • Writes directly to cost-effective, off-the-shelf commodity storage hardware 
  • Offloads up to 91% of processing to ZIIP specialty engines*  
  • Delivers blazing-fast throughput using TCP/IP Hypersockets or OSA connections 
  • Significantly reduces DASD dependence and MLC-related software costs 

How VSA Works 

VSA captures I/O at the lowest level, reading data directly from memory and streaming it across a TCP/IP Hypersocket (a superfast, virtualized Open Systems pipe) or, optionally, through a direct-attached OSA card. This enables transfer speeds in line with what today’s traditional VTL solutions can deliver. 

Because IBM doesn’t allow I/O processing to be offloaded to ZIIPs, Broadcom tackled this limitation with a smart workaround: zEDC hardware compression. Integrated into z15 and z16 processors, zEDC compresses data by an average of 75%, cutting I/O volume by three-quarters. The smaller the payload, the less general CPU activity is needed, keeping MLC impact minimal. 

Security Without Compromise 

Security is also foundational. VSA integrates with IBM z/OS’s Pervasive Encryption key management, securing every file with AES-256 encryption, which is resistant even to quantum computing threats. Data is fully protected, whether on-prem or in cloud object storage. 

Why the VSA Feature Matters 

Broadcom’s CA 1 Flexible Storage with Virtual Storage Adapter closes the gap between high-performance storage and operational cost efficiency. It empowers enterprises to: 

  • Eliminate reliance on costly DASD and VTL hardware for tape workloads 
  • Leverage affordable storage platforms (object or local commodity storage) 
  • Avoid CPU spikes that drive up MLC charges 
  • Secure tape data with encryption keys stored on the mainframe 
  • Gain hybrid cloud agility, without sacrificing mainframe performance 

Conclusion 

With CA 1 Flexible Storage and the new Virtual Storage Adapter, Broadcom is redefining what's possible for mainframe storage. The impossible is now reality; performance, cost-efficiency, and security are all in one solution. 

Whether you're modernizing your backup strategy, offloading legacy VTL infrastructure, or just trying to reduce your mainframe spending, this solution enables you to be a storage rock star while scaling your enterprise's storage architecture thoughtfully. 

* Broadcom lab testing 

 

If you are a CA 1 customer, you can upgrade to CA 1 Flexible Storage today at no additional cost. If you are already running CA 1 Flexible Storage, upgrade now to V15.1 to take advantage of this critical new VSA feature. 

Download the code: https://downloads.broadcom.com/