LVM mirror on GFS2

We have 4 nodes Redhat cluster sharing a GFS2 file system and we use LVM mirror on 2 separate SAN disk for high availibity. With LVM mirror, we noticed a lot of "openais[5695]: [TOTEM] Retransmit List" in the /var/log/messages and application group claimed that I/O writes seem to very slow. Our network engineer captured traffics for non-LVM mirror and LVM mirror and noticed that with LVM mirror there 100 thousand times more packets using multicast address compared to non-LVM mirror.