NAME

iser —

iSCSI Extensions for RDMA (iSER) driver

SYNOPSIS

To compile this driver into the kernel, place the following line in the kernel configuration file:

device iser

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

iser_load="YES"

DESCRIPTION

The iser (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 iscsid(8) and both the kernel and userland are configured using iscsictl(8).

SYSCTL VARIABLES

The following variables are available as both sysctl(8) variables and loader(8) tunables:

kern.iser.debug: Verbosity level for log messages from the iser driver. Set to 0 to disable logging or 1 to warn about potential problems. Larger values enable info and debugging output. Defaults to 0.

HISTORY

The iser subsystem first appeared in FreeBSD 11.0.

AUTHORS

The iser subsystem was developed by Max Gurtovoy <maxg@mellanox.com> and
Sagi Grimberg <sagig@mellanox.com> under sponsorship from Mellanox Technologies.