How Virtual Machines Keep Their Data Separate on Shared Storage

A method for virtual machines to store data in isolated, non-mixed logical storage units to improve security and management efficiency within a shared physical storage pool.

What it covers

This patent describes a way to organize how virtual machines (VMs) talk to physical hard drives. Instead of letting multiple VMs dump their data into the same shared storage bucket, the system creates 'logical units'—essentially private lanes for each VM's virtual disk. A specialized 'virtualized disk I/O handler' sits between the VM and the storage. When a VM wants to read or write data, this handler intercepts the request, checks if it has permission, and maps the request specifically to the correct, isolated logical unit. This prevents data from different VMs from being commingled, which makes it easier to take snapshots or move individual VMs without affecting others.

What it doesn't cover

• —Does not cover storage architectures where data from multiple virtual machines is intentionally stored on the same logical unit.
• —Does not cover physical storage management that lacks a virtualized disk I/O handler for request interception.
• —Does not cover non-virtualized computing environments where direct hardware access is not mediated by a hypervisor.
• —Does not cover storage systems that do not utilize a storage pool abstraction layer.

The clever bit

The innovation is the 'virtualized disk I/O handler' that dynamically modifies disk access requests to map them to specific logical units, effectively acting as a gatekeeper that ensures strict physical isolation for virtual assets.

Why it matters

In data centers, managing storage for thousands of VMs is a massive performance and security challenge. By ensuring that one VM's data cannot be mixed with another's at the logical unit level, this architecture simplifies administrative tasks like backing up specific VMs or moving them between servers. It provides a blueprint for 'clean' storage isolation that is critical for enterprise-grade cloud infrastructure.

Real-world examples

• 1.VMware vSphere storage environments
• 2.Enterprise cloud data centers
• 3.Virtualized server clusters using iSCSI protocols