http://kbase.redhat.com/faq/docs/DOC-19446
Release Found: Red Hat Enterprise Linux 5
Problem
multiple SAN들이 연결된 시스템에서는 , 어떤 디스크가 어떤 SAN인지, 어떤 포트 어떤 연결인지 확인하기 어렵니다.
Resolution
On Red Hat Enterprise Linux 5 에서는 모든 데이타가 /sys 에 저장되어 있고, Fibre Channel 별로 찾을 수 있다..
1) 서버에서 HBA의 Fibre Channel 주소를 찾기위해서는 아래와 같이 실행해라:
# systool -c fc_host -v
(output trimmed for clarity)
Class Device path = "/sys/class/fc_host/host8"
port_name = "0x10000000c9802436"
node_name = "0x20000000c9802436"
Class Device path = "/sys/class/fc_host/host9"
port_name = "0x10000000c9802437"
node_name = "0x20000000c9802437"
각 서버에서, 현재 두개를 가지는 HBA가 현재 host8 와 host9로 동작하는 것을 알 수 있다. (please notice that these numbers can change, they change every time the fibre channel driver is unloaded, reloaded, and can change across reboots). 이 host숫자는 HBTL SCSI addressing 에서의 H-value 이다.
2) 아래의 명령으로 또한 우리는 triplet HBT ( HBTL SCSI addressing) 에 대한 fibre channel target WWN을 확인할 수 있다..
# systool -c fc_transport -v
(output trimmed for clarity)
Class = "fc_transport"
Class Device path = "/sys/class/fc_transport/target8:0:0"
node_name = "0x50060160ba601693"
port_name = "0x500601683a601693"
Class Device path = "/sys/class/fc_transport/target9:0:0"
node_name = "0x50060160ba601693"
port_name = "0x500601683a601693"
Class Device path = "/sys/class/fc_transport/target8:0:1"
node_name = "0x50060160ba601693"
port_name = "0x500601603a601693"
Class Device path = "/sys/class/fc_transport/target9:0:1"
node_name = "0x50060160ba601693"
port_name = "0x500601603a601693"
Where node_name, is the FC WWN of the Storage System, and port_name is the FC WWID of the Storage Processor Port.
3) With the following command, we can determine the mapping between SCSI HBTL addresses and the disks:
(sg_map is part of sg3_utils, and before running sg_map, it is necessary to have the sg module loaded on the system)
# sg_map -x
(output trimmed for clarity)
/dev/sg4 8 0 0 0 0 /dev/sdd
/dev/sg5 8 0 0 1 0 /dev/sde
/dev/sg6 8 0 0 2 0 /dev/sdf
/dev/sg7 8 0 1 0 0 /dev/sdg
/dev/sg8 8 0 1 1 0 /dev/sdh
/dev/sg9 8 0 1 2 0 /dev/sdi
/dev/sg10 9 0 0 0 0 /dev/sdj
/dev/sg11 9 0 0 1 0 /dev/sdk
/dev/sg12 9 0 0 2 0 /dev/sdl
/dev/sg13 9 0 1 0 0 /dev/sdm
/dev/sg14 9 0 1 1 0 /dev/sdn
/dev/sg15 9 0 1 2 0 /dev/sdo
4) From commands on (1), (2) and (3) we have the mapping from disk to HBTL SCSI addresses, and the mapping of SCSI address to fibre channel address. If, for instance, we want to see where the following multipath device is hosted, we do:
disc01 (3600601608e661a01486cd3c7f53ede11) dm-1 DGC,RAID 5
[size=10G][features=0][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=2][active]
\_ 8:0:1:0 sdg 8:96 [active][ready]
\_ 9:0:1:0 sdm 8:192 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 8:0:0:0 sdd 8:48 [active][ready]
\_ 9:0:0:0 sdj 8:144 [active][ready]
5) We know already that it's an EMC Clariion because the vendor is DGC, but I could have LUNs from more than one Clariion on this system, so let's pick /dev/sdj as an example:
/dev/sg10 9 0 0 0 0 /dev/sdj
/dev/sdj = H:B:T:L = 9:0:0:0
Therefore for sdj we have, H=9 and HBT=9:0:0. From (1) and (2) we have:
Host HBA WWN: 0x20000000c9802437
Host HBA WWP: 0x10000000c9802437
Storage System WWN: 0x50060160ba601693
Storage Processor WWP: 0x500601683a601693
6) Doing for all disks:
Local Port Remote port STORAGE
8:0:1:0 sdg 0x10000000c9802436 0x500601603a601693 0x50060160ba601693
9:0:1:0 sdm 0x10000000c9802437 0x500601603a601693 0x50060160ba601693
8:0:0:0 sdd 0x10000000c9802436 0x500601683a601693 0x50060160ba601693
9:0:0:0 sdj 0x10000000c9802437 0x500601683a601693 0x50060160ba601693
ATTENTION: look carefully at the 'Remote port' values, they normally differ only in a few bits.
In this particular case, we see that both sdd and sdj are on the same remote port, and sdg and sdm are on the same ports as well.
7) A storage system can have many ports. In most cases 2 or 4, but the Storage ID should remain the same. In sysfs we have 0x50060160ba601693, which maps perfectly to the storage WWN from the storage admin interface.
Current Storage System Name: AX150
Storage System World Wide Name: 50:06:01:60:BA:60:16:93
