VAAI Plugin Compatibility: Using Multiple Third-Party Storage Plugins on a Single ESXi Host

Products

• VMware vSphere ESXi

Issue/Introduction

Can multiple VAAI (vSphere Storage APIs for Array Integration) plugins from different hardware vendors be safely installed on a single ESXi host? If datastores exist on two different SANs from different vendors, is there a potential for conflict between the vendor-specific plugins?

Environment

• Product: VMware vSphere ESXi 7.x / 8.x
• Storage: Heterogeneous SAN environments (Fiber Channel, iSCSI, or NFS)
• Component: Third-party VAAI Filter Plugins (VIBs)

Resolution

Yes, it is safe to have multiple VAAI plugins from different hardware vendors installed on the same ESXi host. VMware’s Pluggable Storage Architecture (PSA) handles heterogeneous environments through a prioritized Claim Rule system.

How ESXi Prevents Conflicts

• Targeted Claim Rules: VAAI plugins register specific claim rules identifying devices by Vendor ID and Model ID.
• Specific Assignment: During discovery, ESXi scans these rules and attaches the matching plugin to the correct LUN. If no match is found, it defaults to the native T10 SCSI standard.
• Plugin Isolation: Plugins operate independently. A plugin for one vendor will not attempt to manage a device from another because the hardware identifiers will not match.

Important Considerations

• Native Support: Many modern block storage arrays (FC/iSCSI) use the native T10 SCSI standard and may not require a separate plugin.
• NFS Datastores: Vendor-specific plugins are almost always required for VAAI primitives (like hardware-accelerated cloning) on NFS.
• Reboot Requirements: Installing or removing VAAI VIBs typically requires placing the host in Maintenance Mode and rebooting.
• Cross-Array Operations: VAAI offloading (e.g., Hardware Accelerated Move) only works within the same physical array. Moving data between different SANs will revert to software-based copying.

Verification

To verify which VAAI plugin is active for a specific device, run the following command from the ESXi CLI: esxcli storage core device vaai status get