resending this without the 80kb chart

Yesterday morning one of the heads on our 3270 experienced large NFS latency spikes causing our VMware hosts and their VMs to log storage timeouts.
This latency does not correlate to any external metrics like CPU, network, OPS etc.

But in the logs do show CP events on the aggregate hosting the VMs:

Jan 14 05:27:56 [n04:wafl.cp.slovol:warning]: aggregate aggr2 is holding up the CP.

And the EMS log has CP events logged for the duration of the episode - what can we do to prevent these issues?

<wafl_cp_toolong_warning_1
        total_ms="117825"
        total_dbufs="32276"
        clean="4312"
        v_ino="3"
        v_bm="29"
        a_ino="0"
        a_bm="3428"
        flush="1209"/>
</LR>
<LR d="14Jan2013 05:19:38" n="irt-na04" t="1358169578" id="1335304168/148007" p="4" s="Ok" o="wafl_CP_proc" vf="" type="0" seq="633232" >
<wafl_cp_slovol_warning_1
        voltype="aggregate"
        volowner=""
        volname="aggr2"
        volident=""
        nt="35"
        nb="22045"
        clean="1346852"
        v_ino="0"
        v_bm="113"
        a_ino="0"
        a_bm="4"
        flush="0"
        rgid="2"/>

Netapp support wants me to run perfstats, but the issue is not ongoing - things are idle

thanks