.\" Copyright (c) 2013 Edward Tomasz Napierala
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.\" $FreeBSD$
.Dd April 8, 2015
.Dt CTL 4
.Os
.Sh NAME
.Nm ctl
.Nd CAM Target Layer
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following line in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device iscsi"
.Cd "device ctl"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
ctl_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
subsystem provides SCSI disk and processor emulation.
It supports features such as:
.Pp
.Bl -bullet -compact
.It
Disk and processor device emulation
.It
Tagged queueing
.It
SCSI task attribute support (ordered, head of queue, simple tags)
.It
SCSI implicit command ordering support
.It
Full task management support (abort, LUN reset, target reset, etc.)
.It
Support for multiple ports
.It
Support for multiple simultaneous initiators
.It
Support for multiple simultaneous backing stores
.It
Support for VMWare VAAI: COMPARE AND WRITE, XCOPY, WRITE SAME,
and UNMAP commands
.It
Support for Microsoft ODX: POPULATE TOKEN/WRITE USING TOKEN,
WRITE SAME, and UNMAP commands
.It
Persistent reservation support
.It
Mode sense/select support
.It
Error injection support
.It
All I/O handled in-kernel, no userland context switch overhead
.El
.Pp
It also serves as a kernel component of the native iSCSI target.
.Sh SEE ALSO
.Xr ctladm 8 ,
.Xr ctld 8 ,
.Xr ctlstat 8
.Sh HISTORY
The
.Nm
subsystem first appeared in
.Fx 9.1 .
.Sh AUTHORS
The
.Nm
subsystem was written by
.An Kenneth Merry Aq ken@FreeBSD.org .