iser — iSCSI Extensions for RDMA (iSER) driver
Contents
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).
History
The iser subsystem first appeared in FreeBSD 11.0.
Name
iser — iSCSI Extensions for RDMA (iSER) driver
See Also
iscsi(4), iscsi.conf(5), iscsictl(8), iscsid(8)
Synopsis
To compile this driver into the kernel, place the following line in the kernel configuration file:
deviceiser
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
iser_load="YES"
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.
