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.\" $FreeBSD: head/share/man/man4/iser.4 301586 2016-06-08 07:36:00Z trasz $
.Dd June 6, 2016
.Dt ISER 4
.Os
.Sh NAME
.Nm iser
.Nd iSCSI Extensions for RDMA (iSER) driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following line in the
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device iser"
.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
iser_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
(iSCSI Extensions for RDMA) initiator driver extends the iSCSI protocol to RDMA.
It permits data to be transferred directly into and out of SCSI buffers
without intermediate data copies.
iSER uses the RDMA protocol suite to supply higher bandwidth for
block storage transfers (zero copy behavior).
To that fact, it eliminates the
TCP/IP processing overhead while preserving the compatibility with iSCSI protocol.
The initiator is the iSCSI/iSER client, which connects to an iSCSI/iSER target,
providing local access to a remote block device.
The userland component is provided by
.Xr iscsid 8
and both the kernel and userland are configured using
.Xr iscsictl 8 .
.Sh SYSCTL VARIABLES
The following variables are available as both
.Xr sysctl 8
variables and
.Xr loader 8
tunables:
.Bl -tag -width indent
.It Va kern.iser.debug
Verbosity level for log messages from the
.Nm
driver.
Set to 0 to disable logging or 1 to warn about potential problems.
Larger values enable info and debugging output.
Defaults to 0.
.El
.Sh SEE ALSO
.Xr iscsi 4 ,
.Xr iscsi.conf 5 ,
.Xr iscsictl 8 ,
.Xr iscsid 8
.Sh HISTORY
The
.Nm
subsystem first appeared in
.Fx 11.0 .
.Sh AUTHORS
The
.Nm
subsystem was developed by
.An Max Gurtovoy Aq Mt maxg@mellanox.com
and
.An Sagi Grimberg Aq Mt sagig@mellanox.com
under sponsorship from Mellanox Technologies.