Enabling AHV Turbo on AOS 5.5

Nutanix KB 4987

From AOS 5.5, AHV Turbo replaces the QEMU SCSI data path in the AHV architecture for improved storage performance.

For maximum performance, ensure the following on your Linux guest VMs:

Enable the SCSI MQ feature by using the kernal command line:
scsi_mod.use_blk_mq=y ( I put this in a /etc/udev/rules.d/)

Kernels older than 3.17 do not support SCSI MQ.
Kernels 4.14 or later have SCSI MQ enabled by default.
For Windows VMs, AHV VirtIO drivers will support SCSI MQ in an upcoming release.

AHV Turbo improves the storage data path performance even without the guest SCSI MQ support.


Perform the following to enable AHV Turbo on AOS 5.5.

Upgrade to AOS 5.5.
Upgrade to the AHV version bundled with AOS 5.5.
Ensure your VMs have SCSI MQ enabled for maximum performance
Power cycle your VMs to enable AHV Turbo.

Note that you do not have to perform this procedure if you upgrading from AOS 5.5 to a later release. AHV Turbo will be enabled by default on your VMs in that case.


  1. […] While with Windows related guest workloads no tuning of operating system is required to enjoy the benefits of AHV Turbo, it seems that with Linux guest workloads SCSI MQ parameter requires tuning to get the maximum performance with AHV Turbo. More info:¬†Enabling AHV Turbo on AOS 5.5 […]

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