+++ This bug was initially created as a clone of Bug #1348068 +++ Description of problem: When using either a replica 3 or sharded replica 3 volume with virtual machines, profiles that exhibit random writes cause high latencies than can sometimes span several seconds. This has been observed with both fio and iometer as load generators Sequential writes do NOT exhibit this affect Version-Release number of selected component (if applicable): How reproducible: Every time the workload is run this profile is observed Steps to Reproduce: 1. use either an fio workload with random write or an iometer profile (attached) 2. track the latency in the vm with pcp 3. Actual results: High latencies are observed which could impact application response times Expected results: Spikes in random write workloads are accepted - may be in the 10's of milliseconds - but latencies that are between 600ms 2s are a problem Additional info: --- Additional comment from Paul Cuzner on 2016-06-20 01:56 EDT --- Added a screenshot showing the max latency observed from the iometer run. This is from a single vm running the workload (as per the icf file attached to the case)