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existing LUNs get disconnected when new LUN is presented

glennn
Advisor

existing LUNs get disconnected when new LUN is presented

Hi.

i have a bunch of linux servers (SLES9 SP4) and are virtually identical in terms of hw/sw SAN components (i.e. qlogic, module config, driver/firmware version, multipathd config and such).

I noticed that one of those servers disconnect currently mounted LUNs whenever a new LUN is presented to it. I haven't even did a rescan of the scsi bus yet, just presented the vdisk in the array w/c is an eva6100. I've checked the switches and the EVA and i found nothing that could point to a problem.

i'm thinking i bumped into a multipathd bug.

sw verions:

host010:~ # uname -r; rpm -qa | grep multipath; grep qla /etc/modprobe.conf.local
2.6.5-7.317-smp
multipath-tools-0.4.7-75.7
options qla2xxx ql2xmaxqdepth=16 qlport_down_retry=64 ql2xloginretrycount=16 ql2xfailover=0 ql2xlbType=0 ql2xautorestore=0x0 ConfigRequired=0
remove qla2xxx /sbin/modprobe -r --first-time --ignore-remove qla2xxx && { /sbin/modprobe -r --ignore-remove qla2xxx_conf; }

thanks!
2 REPLIES
TwoProc
Honored Contributor

Re: existing LUNs get disconnected when new LUN is presented

My guess is a) too many devices. In Linux systems, there are limits to how many devices you can have. At one time it was 256, but since then, I believe "they" have increased it.
My b) other guess is that you're using a big zone for all of this stuff instead of creating nice clean small zones for certain cards on your server to get certain cards on your storage system.

If you letting multiple hosts see multiple devices in the *same* zone, you can start to see all sorts of crazy stuff, kinda like what you're seeing.
We are the people our parents warned us about --Jimmy Buffett
glennn
Advisor

Re: existing LUNs get disconnected when new LUN is presented

Nope. i only have less than 20 LUNs presented to the said server. As for zoning configurations, only that server sees those LUNs.