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Manual Pages  — HV_VSS_DAEMON


hv_vss_daemon – Hyper-V Volume Shadow Copy Service Daemon



hv_vss_daemon [-dn]


The hv_vss_daemon daemon provides the ability to freeze and thaw the file system for FreeBSD guest partitions running on Hyper-V.

Hyper-V allows administrators to backup or restore the FreeBSD guest partition. Administrators can use Windows Powershell scripts to backup or restore the FreeBSD VM.

The hv_vss_daemon accepts file system freeze and thaw requests from the hv_utils(4) driver and performs the actual file-system operation.

The file system freeze and thaw functionality is useful when the Hyper-V host wants to do live backup of FreeBSD guest. Hyper-V host sends file system freezing request to hv_vss_daemon which conducts the real operation. After successfully freezing file system, Hyper-V host takes a snapshot of the VM. In the future, Hyper-V host can restore the FreeBSD VM through that snapshot.

The options are as follows:
  Run as regular process instead of a daemon for debugging purpose.
  Generate debugging output.


hv_vmbus(4), hv_utils(4), hv_netvsc(4), hv_storvsc(4), hv_kvp(4)


The daemon was introduced in October 2016 and developed by Microsoft Corp.


FreeBSD support for hv_vss_daemon was first added by Microsoft BSD Integration Services Team <Mt bsdic@microsoft.com>.

HV_VSS_DAEMON (8) October 12, 2016

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