NAME

     hv_storvsc — Hyper-V Storage Virtual Service Consumer

SYNOPSIS

     To compile this driver into the kernel, place the following lines in the system kernel
     configuration file:

           device hyperv

DESCRIPTION

     The hv_storvsc driver implements the virtual store device for FreeBSD guest partitions
     running on Hyper-V.  FreeBSD guest partitions running on Hyper-V do not have direct access
     to storage devices attached to the Hyper-V server.  Although a FreeBSD guest can access
     storage devices using Hyper-V's full emulation mode, the performance in this mode tends to
     be unsatisfactory.

     To counter the above issues, the hv_storvsc driver implements a storage Virtual Service
     Consumer (VSC) that relays storage requests from the guest partition to the storage Virtual
     Service Provider (VSP) hosted in the root partition using the high performance data exchange
     infrastructure provided by hv_vmbus(4) driver.  The VSP in the root partition then forwards
     the storage related requests to the physical storage device.

     This driver functions by presenting a SCSI HBA interface to the Comman Access Method (CAM)
     layer.  CAM control blocks (CCBs) are converted into VSCSI protocol messages which are
     delivered to the root partition VSP over the Hyper-V VMBus.

SEE ALSO

     hv_ata_pci_disengage(4), hv_netvsc(4), hv_utils(4), hv_vmbus(4)

HISTORY

     Support for hv_storvsc 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_storvsc was first added by Microsoft BSD Integration Services Team
     <bsdic@microsoft.com>.