Files
scst/srpt
Vladislav Bolkhovitin 8e5bb8a22f Series of patches from Bart Van Assche <bart.vanassche@gmail.com>:
- Added Makefile.scsi.Linux-2.6.24.patch and Kconfig.scsi.Linux-2.6.24.patch
 - Updated Makefile.scsi_tgt to reflect move of the SCST device handlers from scst/src/ to scst/src/dev_handlers/
 - Added Makefile.dev_handlers
 - SCST include path fixed in srpt/ Makefile.in_kernel
 - Added script for converting the SCST source tree to a kernel patch. More comment on it:

The SCST source tree as it exists in the current Subversion repository will 
have to be maintained for some time. And if SCST is submitted for inclusion 
in the mainline kernel, this tree will have to be converted to a kernel 
patch, reviewer comments will have to be processed, and the patch will have 
to be resubmitted. So it's convenient to have a script available that 
converts the Subversion source tree into a kernel patch. The patch below does 
just that: convert the scst and srpt directories into a kernel patch 
(iscsi-scst support will be added later on). I have tested the script 
contained in the patch below as follows:

rm -rf linux-2.6.24
rm -rf /lib/modules/2.6.24-scst
tar xjf ~vanasscb/software/downloads/linux-2.6.24.tar.bz2
cd linux-2.6.24
cp ../.config .
(cd ~vanasscb/software/scst 
&& ~vanasscb/software/scst/scripts/generate-kernel-patch \
2.6.24) | patch -p1
make -j5 bzImage modules && make modules_install install
cp -r /lib/firmware/$(uname -r) /lib/firmware/2.6.24-scst
update-initramfs -k 2.6.24-scst -c
reboot



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@366 d57e44dd-8a1f-0410-8b47-8ef2f437770f
2008-05-13 09:27:16 +00:00
..

SCSI RDMA Protocol (SRP) Target driver for Linux
=================================================

SRP Target driver is designed to work directly on top of OpenFabrics
OFED-1.x software stack (http://www.openfabrics.org) or Infiniband
drivers in Linux kernel tree (kernel.org). It also interfaces with 
Generic SCSI target mid-level driver - SCST (http://scst.sourceforge.net)

NOTES: This SRP Target driver can only compile and work with IB driver
       in Linux vanilla kernel. It does not compile and work with IB
       driver in OFED-1.x packages

       If you want to work with IB driver in OFED-1.x package, you should
       read and follow instruction in README.ofed file


Installation
------------
$ make 
$ make install

To minimize QUEUEFULL conditions, please apply scst_increase_max_tgt_cmds
patch and recompile scst

$ cd ~scst/trunk
$ patch -p0 < srpt/patches/scst_increasa_max_tgt_cmds.patch
$ make scst scst_install srpt srpt_install


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 DO
------
+ Stress test and stabilize the code
+ Performance tuning