This patch contains documentation for SRP target driver. Signed-off-by: Vu Pham <vu@xxxxxxxxxxxx> Signed-off-by: Vladislav Bolkhovitin <vst@xxxxxxxx> --- Documentation/scst/README.srpt | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) diff -uprN orig/linux-2.6.27/Documentation/scst/README.srpt linux-2.6.27/Documentation/scst/README.srpt --- orig/linux-2.6.27/Documentation/scst/README.srpt +++ linux-2.6.27/Documentation/scst/README.srpt @@ -0,0 +1,85 @@ +SCSI RDMA Protocol (SRP) Target driver for Linux +================================================= + +The SRP Target driver is designed to work directly on top of the +OpenFabrics OFED-1.x software stack (http://www.openfabrics.org) or +the Infiniband drivers in the Linux kernel tree +(http://www.kernel.org). The SRP target driver also interfaces with +the generic SCSI target mid-level driver called SCST +(http://scst.sourceforge.net). + +How-to run +----------- + +A. On srp target machine +1. Please refer to SCST's README for loading scst driver and its +dev_handlers drivers (scst_disk, scst_vdisk block or file IO mode, nullio, ...) + +Example 1: working with real back-end scsi disks +a. modprobe scst +b. modprobe scst_disk +c. cat /proc/scsi_tgt/scsi_tgt + +ibstor00:~ # cat /proc/scsi_tgt/scsi_tgt +Device (host:ch:id:lun or name) Device handler +0:0:0:0 dev_disk +4:0:0:0 dev_disk +5:0:0:0 dev_disk +6:0:0:0 dev_disk +7:0:0:0 dev_disk + +Now you want to exclude the first scsi disk and expose the last 4 scsi disks as +IB/SRP luns for I/O +echo "add 4:0:0:0 0" >/proc/scsi_tgt/groups/Default/devices +echo "add 5:0:0:0 1" >/proc/scsi_tgt/groups/Default/devices +echo "add 6:0:0:0 2" >/proc/scsi_tgt/groups/Default/devices +echo "add 7:0:0:0 3" >/proc/scsi_tgt/groups/Default/devices + +Example 2: working with VDISK FILEIO mode (using md0 device and file 10G-file) +a. modprobe scst +b. modprobe scst_vdisk +c. echo "open vdisk0 /dev/md0" > /proc/scsi_tgt/vdisk/vdisk +d. echo "open vdisk1 /10G-file" > /proc/scsi_tgt/vdisk/vdisk +e. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices +f. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices + +Example 3: working with VDISK BLOCKIO mode (using md0 device, sda, and cciss/c1d0) +a. modprobe scst +b. modprobe scst_vdisk +c. echo "open vdisk0 /dev/md0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk +d. echo "open vdisk1 /dev/sda BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk +e. echo "open vdisk2 /dev/cciss/c1d0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk +f. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices +g. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices +h. echo "add vdisk2 2" >/proc/scsi_tgt/groups/Default/devices + +2. modprobe ib_srpt + + +B. On initiator machines you can manualy do the following steps: +1. modprobe ib_srp +2. ipsrpdm -c (to discover new SRP target) +3. echo <new target info> > /sys/class/infiniband_srp/srp-mthca0-1/add_target +4. fdisk -l (will show new discovered scsi disks) + +Example: +Assume that you use port 1 of first HCA in the system ie. mthca0 + +[root@lab104 ~]# ibsrpdm -c -d /dev/infiniband/umad0 +id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4, +dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4 +[root@lab104 ~]# echo id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4, +dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4 > +/sys/class/infiniband_srp/srp-mthca0-1/add_target + +OR + ++ You can edit /etc/infiniband/openib.conf to load srp driver and srp HA daemon +automatically ie. set SRP_LOAD=yes, and SRPHA_ENABLE=yes ++ To set up and use high availability feature you need dm-multipath driver +and multipath tool ++ Please refer to OFED-1.x SRP's user manual for more in-details instructions +on how-to enable/use HA feature + +To minimize QUEUEFULL conditions, you can apply scst_increase_max_tgt_cmds +patch from SRPT package from http://sourceforge.net/project/showfiles.php?group_id=110471 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
