User Manual

Rev 2.3-1.0.1
Mellanox Technologies
163
• To establish a connection with an SRP Target and create an SRP (SCSI) device for that
target under
/dev, use the following command:
echo -n id_ext=[GUID value],ioc_guid=[GUID value],dgid=[port GID value],\
pkey=ffff,service_id=[service[0] value] > \
/sys/class/infiniband_srp/srp-mlx[hca number]-[port number]/add_target
See Section , “SRP Tools - ibsrpdm, srp_daemon and srpd Service Script”, on page 164 for
instructions on how the parameters in this
echo command may be obtained.
Notes:
• Execution of the above “echo” command may take some time
• The SM must be running while the command executes
• It is possible to include additional parameters in the echo command:
• max_cmd_per_lun - Default: 62
• max_sect (short for max_sectors) - sets the request size of a command
• io_class - Default: 0x100 as in rev 16A of the specification (In rev 10 the default was 0xff00)
• tl_retry_count - a number in the range 2..7 specifying the IB RC retry count. Default: 2
• comp_vector, a number in the range 0..n-1 specifying the MSI-X completion vector. Some HCA's
allocate multiple (n) MSI-X vectors per HCA port. If the IRQ affinity masks of these interrupts have
been configured such that each MSI-X interrupt is handled by a different CPU then the comp_vector
parameter can be used to spread the SRP completion workload over multiple CPU's.
• cmd_sg_entries, a number in the range 1..255 that specifies the maximum number of data buffer
descriptors stored in the SRP_CMD information unit itself. With allow_ext_sg=0 the parameter
cmd_sg_entries defines the maximum S/G list length for a single SRP_CMD, and commands whose
S/G list length exceeds this limit after S/G list collapsing will fail.
• initiator_ext - Please refer to Section 9 (Multiple Connections...)
• To list the new SCSI devices that have been added by the echo command, you may use
either of the following two methods:
• Execute “fdisk -l”. This command lists all devices; the new devices are included in this
listing.
• Execute “dmesg” or look at
/var/log/messages to find messages with the names of the
new devices.
3.3.1.1.3 SRP sysfs Parameters
Interface for making ib_srp connect to a new target. One can request ib_srp to connect to a new
target by writing a comma-separated list of login parameters to this sysfs attribute. The supported
parameters are:
id_ext A 16-digit hexadecimal number specifying the eight byte identifier
extension in the 16-byte SRP target port identifier. The target port iden-
tifier is sent by ib_srp to the target in the SRP_LOGIN_REQ request.
ioc_guid A 16-digit hexadecimal number specifying the eight byte I/O controller
GUID portion of the 16-byte tar
get port identifier.
dgid A 32-digit hexadecimal number specifying the destination GID.
pkey A four-digit hexadecimal number specifying the InfiniBand partition
key
.