1.\" 2.\" Copyright (c) 2012 Microsoft Corp. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd September 10, 2013 27.Dt HYPER-V 4 28.Os 29.Sh NAME 30.Nm hv_kvp 31.Nd Hyper-V Key Value Pair Driver 32.Sh SYNOPSIS 33To compile this driver into the kernel, place the following lines in 34the system kernel configuration file: 35.Bd -ragged -offset indent 36.Cd "device hyperv" 37.Ed 38.Sh DESCRIPTION 39The 40.Nm 41driver provides the ability to store, retrieve, modify and delete 42key value pairs for 43.Fx 44guest partitions running on Hyper-V. 45Hyper-V allows administrators to store custom metadata in the form 46of key value pairs inside the 47.Fx 48guest partition. 49Administrators can use Windows Powershell scripts to add, read, 50modify and delete such key value pairs. 51.Pp 52The driver is bare bones and merely forwards requests to its counterpart 53user mode daemon, 54.Xr hv_kvp_daemon 8 . 55The daemon maintains pools of key value 56pairs and does the actual metadata management. 57.Pp 58The same driver and daemon combination are also used to set and get 59IP addresses from a 60.Fx 61guest. 62.Pp 63The set functionality is particularly 64useful when the 65.Fx 66guest is assigned a static IP address and is failed over from one 67Hyper-V host to another. 68After failover, Hyper-V uses the set IP functionality to automatically 69update the 70.Fx 71guest's IP address to its original static value. 72.Pp 73On the other hand, the get IP functionality is used to update the guest IP 74address in the Hyper-V management console window. 75.Sh SEE ALSO 76.Xr hv_ata_pci_disengage 4 , 77.Xr hv_netvsc 4 , 78.Xr hv_storvsc 4 , 79.Xr hv_utils 4 , 80.Xr hv_vmbus 4 , 81.Xr hv_kvp_daemon 8 82.Sh HISTORY 83Support for 84.Nm 85first appeared in 86.Fx 10.0 . 87The driver was developed through a joint effort between Citrix 88Incorporated, Microsoft Corporation and Network Appliance Incorporated. 89.Sh AUTHORS 90.An -nosplit 91.Fx 92support for 93.Nm 94was first added by 95.An Microsoft BSD Integration Services Team Aq Mt bsdic@microsoft.com . 96