[ovirt-users] oVirt Instability with Dell Compellent via iSCSI/Multipath

[Chris Jones - BookIt.com Systems Administrator]

> Is there maybe some IO problem on the iSCSI target side?
> IIUIC the problem is some timeout, which could indicate that the target
> is overloaded.

Maybe. I need to check with Dell. I did manage to get it to be a little 
more stable with this config.

defaults {
     polling_interval 10
     path_selector "round-robin 0"
     path_grouping_policy multibus
     getuid_callout          "/usr/lib/udev/scsi_id --whitelisted 
--replace-whitespace --device=/dev/%n"
     path_checker readsector0
     rr_min_io_rq 100
     max_fds 8192
     rr_weight priorities
     failback immediate
     no_path_retry fail
     user_friendly_names no
}
devices {
   device {
     vendor                   COMPELNT
     product                  "Compellent Vol"
     path_checker             tur
     no_path_retry            fail
   }
}

I referenced it from 
http://en.community.dell.com/techcenter/enterprise-solutions/w/oracle_solutions/1315.how-to-configure-device-mapper-multipath. 
I modified it a bit since that is Red Hat 5 specific and there have been 
some changes.

It's not crashing anymore but I'm still seeing storage warnings in 
engine.log. I'm going to be enabling jumbo frames and talking with Dell 
to figure out if it's something on the Compellent side. I'll update here 
once I find something out.

Thanks again for all the help.