After failover occurs, most data on HDFS will no longer be available locally, which can result in a significant performance overhead.

To resolve this, a REWRITE operation (see  HA Configuration Parameters) can be run as part of the failover process to re-locate the data. Doing so, however, can take a significant amount of time and will increase the total amount of time VectorH is down. For details, see How to Add and Remove Slave Nodes.