HYPER-V(4)

NAME
hv_ata_pci_disengage - Hyper-V ATA PCI Disengage driver

SYNOPSIS
The hv_ata_pci_disengage driver prevents the native FreeBSD ATA driver from loading in the presence of Hyper-V.

DESCRIPTION
FreeBSD guests running on Hyper-V can take advantage of the Hyper-V Storage Virtual Consumer (hv_storvsc) for using their IDE devices. Since the ATA driver serves IDE devices as well, there is a chance that the ATA driver may interfere with the operations of hv_storvsc. The hv_ata_pci_disengage driver avoids conflicts between the ATA driver and hv_storvsc by disabling the ATA driver when the FreeBSD guest is booting. A side effect of disabling the ATA driver is that CDROM may become inoperational on FreeBSD guest partitions. If CDROM access is a must then users may use "set hw.ata.disk_enable=1" at boot time to prevent the ATA driver from being disabled.

SEE ALSO
hv_vmbus(4), hv_utils(4), hv_netvsc(4), hv_storvsc(4)

HISTORY
Support for Hyper-V in the form of ports was first released in September 2013. The driver was developed through a joint effort between Citrix Inc., Microsoft Corp. and Network Appliance Inc..

AUTHORS
-nosplit FreeBSD support for hv_ata_pci_disengage was first added by Microsoft BSD Integration Services Team <bsdic@microsoft.com>.