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4ac6d7a26d
There is no need for a detect() method - code that is present in such a method can be moved to module_init(). Hence declare this method obsolete. Leave the detect pointer member in the target template for now for out-of-tree SCST drivers. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> with some improvements git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6113 d57e44dd-8a1f-0410-8b47-8ef2f437770f
IBM Virtual SCSI Target (ibmvstgt)
==================================
Introduction
------------
The virtual SCSI (VSCSI) protocol as defined in [2] is a protocol that allows
one logical partition (LPAR) to access SCSI targets provided by another LPAR.
The LPAR that provides one or more SCSI targets is called the VIO server or
VIOS. The ibmvstgt driver is a VIOS driver that makes it possible to access
exported target devices via the VSCSI protocol.
Setup
-----
After having configured the LPARs, boot the LPARs and load the ibmvstgt kernel
module in the VIOS. After the target driver has been loaded, verify that a
message similar to the following appears in the initiator kernel log:
ibmvscsi 30000028: partner initialized
ibmvscsi 30000028: host srp version: 16.a, host partition VIOS3-P6 (40), OS 2, max io 67108864
ibmvscsi 30000028: sent SRP login
ibmvscsi 30000028: SRP_LOGIN succeeded
In the above log messages, the number 30000028 refers to the VIOS. The last
two digits, 0x28, refer to the VIOS partition number (0x28 = 40).
The next step is to decide which SCSI devices to export. Here is an example of
a configuration in which 16 RAM disks have been exported (see also [1] for
more information):
# ls /sys/kernel/scst_tgt/devices
2:0:0:0 ram000 ram001 ram002 ram003 ram004 ram005 ram006 ram007
ram008 ram009 ram010 ram011 ram012 ram013 ram014 ram015
Next, set the vendor ID, product ID etc. fields via sysfs. These fields
must be set to the following values to allow AIX initiators to recognize
SCST devices:
* The Vendor ID (t10_vend_id) must be set to "IBM".
* The Product ID (prod_id) must be set either to "VDASD blkdev" for SCSI disks
or "VOPTA blkdev" for a SCSI CD-ROM.
* The Product Revision Level (prod_rev_lvl) must be set to "0001".
* The Vendor Specific Information in the INQUIRY response (inq_vend_specific)
must be set to the serial number. The serial number is available in the
"usn" sysfs attribute.
After this step a LUN has to be assigned to each exported SCSI device. Some
non-Linux initiator operating systems only accept LUN numbes that are
multiples of 256 and require that the LUN addressing method is used.
Assigning LUN numbers is possible e.g. as follows:
lun=0
for name in ram000 ram001 ram002 ram003 ram004 ram005 ram006 ram007 \
ram008 ram009 ram010 ram011 ram012 ram013 ram014 ram015
do
lun=$((lun+256))
echo "add $name $lun" \
>/sys/kernel/scst_tgt/targets/ibmvstgt/ibmvstgt_target_0/luns/mgmt
done
echo 1 >/sys/kernel/scst_tgt/targets/ibmvstgt/ibmvstgt_target_0/enabled
The result of the above commands will be as follows:
# cat /sys/kernel/scst_tgt/targets/ibmvstgt/ibmvstgt_target_0/addr_method
LUN
# ls /sys/kernel/scst_tgt/targets/ibmvstgt/ibmvstgt_target_0/luns
256 512 768 1024 1280 1536 1792 2048 2304 2560 2816 3072 3328 3584 3840 4096
mgmt
# cat /sys/kernel/scst_tgt/targets/ibmvstgt/ibmvstgt_target_0/enabled
1
After SCST has been configured, make the new configuration available to the
initiator by rescanning the SCSI bus, e.g. as follows:
# rescan-scsi-bus --hosts=2 --ids=0-31
# lsscsi 2:
[2:0:1:0] disk IBM VDASD blkdev 0001 /dev/sdb
[2:0:2:0] disk IBM VDASD blkdev 0001 /dev/sdc
[2:0:3:0] disk IBM VDASD blkdev 0001 /dev/sdd
[2:0:4:0] disk IBM VDASD blkdev 0001 /dev/sde
[2:0:5:0] disk IBM VDASD blkdev 0001 /dev/sdf
[2:0:6:0] disk IBM VDASD blkdev 0001 /dev/sdg
[2:0:7:0] disk IBM VDASD blkdev 0001 /dev/sdh
[2:0:8:0] disk IBM VDASD blkdev 0001 /dev/sdi
[2:0:9:0] disk IBM VDASD blkdev 0001 /dev/sdj
[2:0:10:0] disk IBM VDASD blkdev 0001 /dev/sdk
[2:0:11:0] disk IBM VDASD blkdev 0001 /dev/sdl
[2:0:12:0] disk IBM VDASD blkdev 0001 /dev/sdm
[2:0:13:0] disk IBM VDASD blkdev 0001 /dev/sdn
[2:0:14:0] disk IBM VDASD blkdev 0001 /dev/sdo
[2:0:15:0] disk IBM VDASD blkdev 0001 /dev/sdp
[2:0:16:0] disk IBM VDASD blkdev 0001 /dev/sdq
References
----------
[1] SCST Configuration Interface, Documentation/scst/README.scst.
[2] Power.org Standard for Power Architecture Platform Requirements (PAPR)
(Workstation, Server), Version 2.4, December 7, 2009, http://www.power.org.
[3] Virtual I/O (VIO) and Virtualization, IBM Developerworks, 2010,
http://www.ibm.com/developerworks/wikis/display/virtualization/VIO.