You need more space on the "m5san01" group; you can either delete some replicas, delete some volumes (if you have any at on that group) or buy another enclosure and add it to the group/pool (or if you bought a unit with just 8 drives, you could buy the 8 additional drives).
Does any one know how to stop this messages? I started moving data to my san and started getting them.  I was able to increase the replica space but not I can't anymore. Please help!
Replica Reserve