Infrastructure Software

I have OVS installed and it is attached to an EMC Clariion CX3 SAN. I installed it with the 'linux mpath' option and it found the SAN OK. The problem is, it seems to only find one of the paths successfully. Devices /dev/sdc and /dev/sde are OK, but devices /dev/sdb and /dev/sde aren't. I've tried a lot of things, including messing with the multipath.conf file, to no avail. Whenever I issue a command that hits the SAN, the console displays errors like "end_request: I/O error, dev sdb, sector 0". I'm not sure what I'm doing wrong.

multipath.conf:
defaults {
user_friendly_names yes
}

blacklist {
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^(hd|xvd|vd)[a-z]*"
wwid "*"
}

# Make sure our multipath devices are enabled.

blacklist_exceptions {
wwid "36006016077211f00c4ddf4f7104ce011"
}

devices {
device {
vendor "DGC"
product "*"
path_grouping_policy failover
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout "/sbin/mpath_prio_emc /dev/%n"
hardware_handler "1 emc"
features "1 queue_if_no_path"
no_path_retry 300
path_checker emc_clariion
failback immediate
}
}

multipath -ll:
mpath0 (36006016077211f00c4ddf4f7104ce011) dm-0 DGC,RAID 5
[size=500G][features=1 queue_if_no_path][hwhandler=1 emc][rw]
\_ round-robin 0 [prio=2][active]
\_ 1:0:1:0 sdc 8:32 [active][ready]
\_ 2:0:1:0 sde 8:64 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 1:0:0:0 sdb 8:16 [active][ready]
\_ 2:0:0:0 sdd 8:48 [active][ready]

mounted.ocfs2 -d:
Device FS UUID Label
/dev/sdc1 ocfs2 79a1769b-2ca4-4c2c-b6ce-37b84c5db27b /OVS
/dev/sde1 ocfs2 79a1769b-2ca4-4c2c-b6ce-37b84c5db27b /OVS
/dev/dm-1 ocfs2 79a1769b-2ca4-4c2c-b6ce-37b84c5db27b /OVS

Any help would be greatly appreciated.