====== RedHat Enterprise Linux ======
===== WWN =====
==== Qlogic HBA WWN ====

How to identify/get QLogic WWN on Red Hat Enterprise Linux 5 (RHEL5).

First identify your installed or recognised

<code bash >
# lspci | grep -i fibre
04:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
04:00.1 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
05:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
05:00.1 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
</code>

On  Red Hat Enterprise Linux 5 (5.x) is on /sys/class/fc_host/hostX/port_name

(X is your device 1,2,3,…N)

For get use:
<code bash >
cat /sys/class/fc_host/hostX/port_name
</code>

Sample with multiple HBA (Fibre) QLogic
<code bash >
# ls /sys/class/fc_host/
host1  host2  host3  host4
# cat /sys/class/fc_host/host[1-4]/port_name
0x2100001b32936e24
0x2101001b32b36e24
0x2100001b32932821
0x2101001b32b32821
</code>
On Red Hat Enterprise Linux 4 (AS/ES) is on /proc/scsi/qla2xxx/1 (1,2,3,..N)

Sample:
<code bash >
# egrep [node|port] /proc/scsi/qlx2xxx/0
scsi-qla0-adapter-node=200000e08b1c19f2;
scsi-qla0-adapter-port=210000e08b1c19f2;
</code>

==== Other HBA WWN ====

Verified on Suse Linux Enterprise Server and CentOS/Redhat

The info is in

<code bash>
/sys/class/scsi_host/hostN/device/fc_host/hostN/port_name
</code>
Where “N” is the number of device for your fiber HBAs.

Unfortunately, you may have a large number of listings depending on the different cards (besides fiber HBA) that you have on your system. In my example, I have six listings:

<code>
host0
host1
host2
host3
host4
host5
</code>
but only two represent a fiber HBA.

So you may have to do some digging. In my case they are

<code>
host4
host5

</code>
(I have two HBAs installed)

So …
<code bash>
[root@centos63node01 ~]# cat /sys/class/scsi_host/host4/device/fc_host/host4/port_name
0x5001438003af1ffc
[root@centos63node01 ~]# cat /sys/class/scsi_host/host5/device/fc_host/host5/port_name
0x5001438003af1b9e
[root@centos63node01 ~]#
</code>
Here is a one liner command to find it. This is added 2/28/2014 per a comment on my blog made by reader Liivo L (THANKS Liivo L!!)
<code bash>
[root@testlinux ~]# cat /sys/class/scsi_host/host*/device/fc_host/host*/node_name
0x20000024ff5763d2
0x20000024ff5763d3
[root@testlniux ~]#
</code>
This is the way I did have it written down prior to Liivo L’s comment. Here’s my shortcut bash command if you don’t want to look around. This command is executed in the /sys/class/scsi_host directory. While the one liner command is easier, this is a nice example of using a “for do done” loop on your command line (very handy for many other things)
<code bash>
[root@centos63node01 scsi_host]# for i in 0 1 2 3 4 5; do cat host$i/device/fc_host/host$i/port_name; done
cat: host0/device/fc_host/host0/port_name: No such file or directory
cat: host1/device/fc_host/host1/port_name: No such file or directory
cat: host2/device/fc_host/host2/port_name: No such file or directory
cat: host3/device/fc_host/host3/port_name: No such file or directory
0x5001438003af1ffc
0x5001438003af1b9e
[root@centos63node01 scsi_host]#

</code>

===== MPIO =====

<code bash mpio.sh>
mpathconf --user_friendly_names y  --find_multipaths y --with_multipathd  y
/etc/init.d/multipathd start



for i in /sys/class/fc_host/host*
do
echo '1' > $1/issue_lip
done

for i in /sys/class/scsi_host/host*
do
echo '- - -' > $i/scan
done
</code>

{{tag>hint}}