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authormav <mav@FreeBSD.org>2017-03-25 11:48:12 +0000
committermav <mav@FreeBSD.org>2017-03-25 11:48:12 +0000
commitad6c10337c7ebe1a0db4534a4c1c07ff87eaeea6 (patch)
tree9403e05c2a35b3ab7c78561f56d0eaa97dbc5f89 /share
parent6a366b3db80783e8ea43d15b557353ad7d483a52 (diff)
downloadFreeBSD-src-ad6c10337c7ebe1a0db4534a4c1c07ff87eaeea6.zip
FreeBSD-src-ad6c10337c7ebe1a0db4534a4c1c07ff87eaeea6.tar.gz
MFC r315087, r315146:
Improve ctl(4) description, including frontends and backends.
Diffstat (limited to 'share')
-rw-r--r--share/man/man4/ctl.481
1 files changed, 61 insertions, 20 deletions
diff --git a/share/man/man4/ctl.4 b/share/man/man4/ctl.4
index 7e6cb8d..a22cda8 100644
--- a/share/man/man4/ctl.4
+++ b/share/man/man4/ctl.4
@@ -1,5 +1,5 @@
.\" Copyright (c) 2013 Edward Tomasz Napierala
-.\" Copyright (c) 2015 Alexander Motin <mav@FreeBSD.org>
+.\" Copyright (c) 2015-2017 Alexander Motin <mav@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
@@ -24,12 +24,12 @@
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
-.Dd September 27, 2015
+.Dd March 11, 2017
.Dt CTL 4
.Os
.Sh NAME
.Nm ctl
-.Nd CAM Target Layer / iSCSI target
+.Nd CAM Target Layer / SCSI target subsystem
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following line in your
@@ -48,12 +48,12 @@ ctl_load="YES"
.Sh DESCRIPTION
The
.Nm
-subsystem provides SCSI disk and processor emulation.
+subsystem provides SCSI target devices emulation.
It supports features such as:
.Pp
.Bl -bullet -compact
.It
-Disk, processor and cdrom device emulation
+Disk, CD-ROM and processor device emulation
.It
Tagged queueing
.It
@@ -61,32 +61,73 @@ 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.)
+Full task management support (abort, query, reset, etc.)
.It
-Support for multiple ports
+Support for multiple ports, initiators, targets and backing stores
.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
+Support for VMWare VAAI and Microsoft ODX offload (COMPARE AND WRITE,
+XCOPY, POPULATE TOKEN/WRITE USING TOKEN, WRITE SAME and UNMAP)
.It
Persistent reservation support
.It
-Mode sense/select support
+Extensive VPD/mode/log pages support
.It
-Error injection support
+Featured error reporting, error injection and basic SMART support
.It
High Availability clustering support with ALUA
.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.
+The
+.Nm
+subsystem includes multiple frontends to provide access using different
+transport protocols and implementations:
+.Bl -tag -width cfumass
+.It camsim
+Provides access for local system via virtual initiator mode
+.Xr CAM 4
+SIM.
+.It camtgt
+Provides access for remote systems via target mode
+.Xr CAM 4
+SIMs, such as Fibre Channel
+.Xr isp 4
+and
+.Xr mpt 4 .
+.It cfumass
+Provides access for remote systems via USB Mass Storage Class
+Bulk Only (BBB) Transport.
+.It ha
+Internal frontend used to receive requests from other node ports in
+High Availability cluster.
+.It ioctl
+Provides access for local user-level applications via
+.Xr ioctl 2
+based API.
+.It iscsi
+Combined with
+.Xr iscsi 4
+and
+.Xr ctld 8 ,
+provides access for remote systems via iSCSI protocol.
+.It tpc
+Internal frontend used to receive requests from Third Party Copy engine,
+implementing copy offload operations.
+.El
+.Pp
+The
+.Nm
+subsystem includes two backends to create logical units using different
+kinds of backing stores:
+.Bl -tag -width ramdisk
+.It block
+Stores data in ZFS ZVOLs, files or raw block devices.
+.It ramdisk
+Stores data in RAM, that makes it mostly useful for performance testing.
+Depending on configured capacity can work as black hole, thin or thick
+provisioned disk.
+.El
.Sh SYSCTL VARIABLES
The following variables are available as both
.Xr sysctl 8
@@ -146,7 +187,7 @@ primary;
.It 1
secondary.
.El
-This role can be overriden on per-LUN basis using "ha_role" LUN option,
+This role can be overridden on per-LUN basis using "ha_role" LUN option,
so that for one LUN one node is primary, while for another -- another.
Role change from primary to secondary for HA modes 0 and 2 closes backends,
the opposite change -- opens.
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