Hi,
If you have this type of event (latency), try to take note if this matters ocurs at the same time all days, or same day every week. Do you need to check too the Messages logs, and if is possible run any tool from your storage vendor in order to obtain performance metrics.
"Device naa.600c0ff0001050abc90f944e01000000
performance has deteriorated. I/O latency
increased from average value of 14539
microseconds to 6509639 microseconds.
warning"
Regards