| HYPER-V(4) | Device Drivers Manual | HYPER-V(4) | 
NAME¶
hv_ata_pci_disengage —
    Hyper-V ATA PCI Disengage driver
SYNOPSIS¶
To compile this driver into the kernel, place the following lines in the system kernel configuration file:
device hypervDESCRIPTION¶
The hv_ata_pci_disengage driver prevents
    the native FreeBSD ATA driver from loading in the
    presence of Hyper-V. FreeBSD guests running on
    Hyper-V can take advantage of the Hyper-V Storage Virtual Consumer
    (hv_storvsc(4)) 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(4). The
    hv_ata_pci_disengage driver avoids conflicts between
    the ATA driver and hv_storvsc(4) 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¶
HISTORY¶
Support for hv_ata_pci_disengage first
    appeared in FreeBSD 10.0. The driver was developed
    through a joint effort between Citrix Incorporated, Microsoft Corporation,
    and Network Appliance Incorporated.
AUTHORS¶
FreeBSD support for
    hv_ata_pci_disengage was first added by
    Microsoft BSD Integration Services Team
    <bsdic@microsoft.com>.
| September 10, 2013 | Debian |