Dual Port FC HBA failover on Debian?

_phenix_ · 11-13-2007, 05:21 AM

Hi Forum,

i used the search function but didn't really find something that helps me out.

I am using a dual port fibre channel hba (emulex) to connect my server to the fc-san, devices are correctly identified by the lpfc module as "/dev/sda" and "/dev/sdb". The only problem remaining for me is now, how can i set up the hba, so he uses them either active/active or active/passive? the server is a hp server where binary packages for suse and rhel exist.

any help, rtfm's or links to information i overlooked would be appreciated.

thx
_phenix_

stokes · 11-13-2007, 05:31 AM

Not sure about emulex, but for qlogic cards on hp servers you have to use a specific driver to put the card into either active-active or failover mode. I had some problems with this recently so know a little about it. With the qlogic cards you can tell which mode they are in by viewing the output of cat /proc/scsi/qlaxxxx/0 or 1, grep for fo which indicates the card is configured as a failover. Maybe this will help?!

_phenix_ · 11-13-2007, 05:52 AM

Hi stokes,

i haven't got any /proc/scsi/qla*,
all information i found out in /proc/scsi was:

Code:

Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: HITACHI  Model: OPEN-V*2         Rev: 5009
  Type:   Direct-Access                    ANSI  SCSI revision: 03
Host: scsi1 Channel: 00 Id: 00 Lun: 00
  Vendor: HITACHI  Model: OPEN-V*2         Rev: 5009
  Type:   Direct-Access                    ANSI  SCSI revision: 03

where scsi0/1 are the two hba ports, hitachi is the san in the background. i don't know if the "direct-access" type has something to do with this, but if it has, i'll post it in here.

stokes · 11-13-2007, 07:47 AM

qla is for qlogic cards only, which is why you don't have it on your server. What do you have if you "ls /proc/scsi/*" ?

_phenix_ · 11-13-2007, 08:29 AM

only "/proc/scsi/scsi" where i posted the cat-output above.

according to a colleague of mine, qlogic-cards could be configured for failover in modules.conf with ql2xfailover=1.

Only that neither debian has no modules.conf nor can i find the right parameters that could be put in a relevant file (whilst searching the emulex documentation).

_phenix_ · 11-13-2007, 10:36 AM

Debian automatically identifies the dual-port HBA with the kernel module lpfc, all i had to do was search for a software-raid solution that supported multipathing.

the tool is called mdadm and with the following command a new "raid"-device can be created and after filesystem-creation normally mounted.

[code]
mdadm -Cv /dev/md0 --level=multipath -n2 /dev/sda /dev/sdb
[code]

i still have to test the stability of the driver, but so far it looks good.

thx
_phenix_

EDIT: admins could place a "solved" tag or whatever in front of the thread, with usual thread-editing it doesn't seem to work