topic Re: RHEL 4 LUNS not visible on one PATH in Operating System - Linux

RHEL 4 LUNS not visible on one PATH

brian_31 — Sat, 19 Mar 2011 13:04:18 GMT

We have a RHEL 4 server, where i see on one qlogic HBA all the PATHS to luns, but on the other adapter i do not. if i cd /sys/class/scsi_host/host1 then i see all the targets but do not on other host (host2), i have rebooted and still no help, i have also tried the echo “- – -” > /sys/class/scsi_host/host2/scan recommended in the online storge config guide, but no help. Could someone please guide here? I do not see any errors with that HBA.

Thanks

Brian.

Re: RHEL 4 LUNS not visible on one PATH

Matti_Kurkela — Sat, 19 Mar 2011 16:24:14 GMT

Try this command:

echo 1 > /sys/class/fc_host/host2/issue_lip

It should cause the 2nd FC card to reset itself, making the fibre link go down and then up again. Since your 2nd card is not seeing any LUNs at the moment, this should not cause any harm.

You should see the link down/link up messages at the end of the "dmesg" listing.

Then scan again:
echo "- - -" > /sys/class/scsi_host/host2/scan

If this does not help, there might be problems with your SAN zoning/masking settings. In other words, either a SAN switch or the storage system itself is not allowing the 2nd HBA to see the LUNs. In that case, verify that your SAN admin has the correct WWN for your 2nd HBA, and ask him/her to double-check the SAN configuration.

MK

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Sat, 19 Mar 2011 18:57:02 GMT

Matti

I do not even see a fc_host under /sys/class, i only see scsi_host. Please let me know what should i do?

Thanks

Brian.

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Sat, 19 Mar 2011 19:01:34 GMT

Also there are 32 luns on each path presented, so RHEL 4 should see 64 luns on 2 PATHS. Just a info. is there any limitation in modprobe.conf with LUN limits with qlogic??

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Mon, 21 Mar 2011 14:01:25 GMT

I noticed something like a reset but no fc_host directory? another question is there any change to make more luns visible like options scsi_mod max_scsi_luns=128??

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

Alzhy — Mon, 21 Mar 2011 15:53:07 GMT

Not really familiar with RHEL 4 but you can try installing Qlogic SAN Surfer (scli) and see what's going on.

Other things to check, make sure host2 is indeed your 2nd Qlogic HBA.

Under sys/class/scsi_host/host2:

cat out the following:

model*, state

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Mon, 21 Mar 2011 18:03:59 GMT

I have verified that host2 is indeed the 2nd HBA. scli is not much help as the hosts does not see the new LUN's.

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

Alzhy — Mon, 21 Mar 2011 18:14:21 GMT

Using scli, can you discern if the switch port port-id is seen by your 2nd HBA? Likewise, if you've access to the SAN switch, can you check if the 2nd HBA is logged in to the port it is plugged in to and you can see the HBA's WWID?

If all checks well and good, then next to check is your zoning and EVA Host Group definition sir -- mak sure the hosthroup has the correct HBA wwids defined.

Ciao.

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Mon, 21 Mar 2011 19:05:48 GMT

Good idea!. How do i see the switch port port-id from scli for the 2nd HBA? This will narrow it down..

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

Alzhy — Mon, 21 Mar 2011 19:28:00 GMT

scli

HBA Paramaters
Select HBA
Display HBA Parameters

First Line should show the Switch Port ID:

HBA Instance 6: QLE2462 Port 1 WWPN 21-00-00-1B-32-97-83-61 PortID 05-E6-00

In my case, it is logged on on Switch Port ID 0x05e600 on my Brocade SW48K Director.

HTH

Normally though, such data is in a file in /sys/class/fc_host/hostN/port_id

But you seem to say that path is not on an RHEL 4 system.

Re: RHEL 4 LUNS not visible on one PATH

TwoProc — Mon, 21 Mar 2011 19:36:49 GMT

On the adapter that's not seeing anything... if you plug and then unplug the SAN line, do you see the plugin/unplug events showing up in dmesg (/var/log)?
If so, do you see the controller listed in the events output? Do you have activity/status lights?

It would help verify that it's really there as far as the OS and hardware are concerned.

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Wed, 23 Mar 2011 15:17:50 GMT

Yes the fc_host is not present in this RHEL 4 box, I did find the port -id for both hba's. One other thing in noted in modprobe.conf was an entry
options scsi_mod max_luns=256

is this syntax correct?

Thanks

Brian.

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Wed, 13 Apr 2011 22:41:14 GMT

We atill have this issue. SAN team has checked everything from their side and find no problems, next is to replace the HBA on host2 although there seems no errors showing up, any ideas??

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

Simon Hargrave — Thu, 14 Apr 2011 05:46:30 GMT

Are you using HP supplied qlogic drivers or native red hat? If HP (you should see /proc/scsi/qla2xxx directory) then perhaps to have them configured in qlogic multipath mode? (check modprobe.conf).

If that is the case then I would expect to see what you are seeing. The qlogic driver 'hides' all but one path for each Lun from the SCSI subsystem , so you only see one path.

I can check the parameter names when I get to work (posting this from mobile).

Re: RHEL 4 LUNS not visible on one PATH

Simon Hargrave — Thu, 14 Apr 2011 07:14:04 GMT

Look for the option ql2xfailover=1 against the qla2xxx driver in /etc/modprobe.conf. You can also cat /sys/module/qla2xxx/ql2xfailover.

If failover is enabled, then you can then use the SANSurfer tool to enumerate the individual paths.

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Fri, 22 Apr 2011 14:37:52 GMT

Simon

Nail on the head! I see the cat /sys/module/qla2xxx/ql2xfailover set to 1, but the modprobe.conf file does not have failover to 1. Here it is from modprobe.conf

grep -i qla /etc/modprobe.conf
alias scsi_hostadapter1 qla2xxx_conf
alias scsi_hostadapter2 qla2400
options qla2xxx ql2xmaxqdepth=2
install qla2xxx /sbin/modprobe qla2xxx_conf; /sbin/modprobe --ignore-install qlx
remove qla2xxx /sbin/modprobe -r --first-time --ignore-remove qla2xxx && { /sbi}
options qla2xxx extended_error_logging=1
options qla2xxx ql2xfailover=0

so how could the /sys/module/qla2xxx/ql2xfailover be set to 1? Please clarify ASAP. Thanks for all the support.

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Fri, 22 Apr 2011 17:21:37 GMT

confused?? how would modprobe.conf be set to 0 for failover and how could the /sys/module/qla2xxx/ql2xfailover be set to 1? host2 is not seeing the PATH? could someone explain this situation please?

Thanks

Brian

Re: RHEL 4 LUNS not visible on one PATH

brian_31 — Wed, 27 Apr 2011 16:33:37 GMT

Any Thoughts??

Thanks

Brian