qlogic QMH2462 + 2012FC Array - Multipath Setup

[Rob_69_1]

Hi all, I'm struggling to setup a working Multipath setup using the above listed hardware.

Up to now, everything works nicely at boot.

"multipath -ll" gives correct output, all ok.

BUT if for testing purposes, I try to shutdown an FC switch (there are 2 of them of course), or a Disk Array controller...

SOMETIMES it fails over.

MORE OFTEN I get several "I/O errors", "Detected aborted journal", "Remounting filesystem read-only".

After that, as the filesystem is read-only, system is unusable. Only option is reboot.

Therefore I'm desperately looking for a list of CORRECT vendor-specific parameters. Any of you experts have a config like mine?

In /etc/modprobe.conf I'm using the following entries (QLOGIC QMH2462 SPECIFIC):
options qla2xxx ql2xmaxqdepth=16 qlport_down_retry=10 ql2xloginretrycount=30

And in /etc/multipath.conf I'm using the following entries (2012FC SPECIFIC):
### ADD THE FOLLOWING BLACKLIST AFTER"defaults user_friendly_names yes" SECTION
## Blacklist non-SAN devices
devnode_blacklist {
devnode "sd[a]$"
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
devnode "^cciss!c[0-9]d[0-9]*"
}
devices{
device
{
vendor "HP"
product "MSA2[02]12fc|MSA2012i"
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
hardware_handler "0"
path_selector "round-robin 0"
path_grouping_policy multibus
failback immediate
rr_weight uniform
no_path_retry 18
rr_min_io 100
path_checker tur
}
}

Any ideas, clues, help to get to a reliable situation would be greatly appreciated... Thank you.

[Rob_69_1]

All, I'm sorry for the "noise". As this is my first multipath setup, I just missed... Ahem... starting up the multipathd daemon.

Therefore, configuration was correct... But as a path was failing, nobody was saying "hey, switch path". I'm still wondering how, once every 10 times, it was apparently failing over... Maybe it could happen just under particular circumstances.

Well, it works. The parameters that I listed in the above message looks to be correct, then. Maybe it's going to be useful to somebody, sooner or later.

Thank you.