While discussing a remote replication solution consisting of two HP 3PAR StoreServ arrays, the customer asks you about performance penalties when implementing synchronous replication to a second HP…

Synchronous replication ensures data consistency by requiring a write to be synchronously committed to both the source array and the remote array before the I/O is acknowledged back to the host. This round-trip latency directly increases the time taken for write operations on the source array, thus affecting write performance.

Synchronous replication primarily impacts write performance due to the need for remote acknowledgment; read operations are typically served locally from the source array without remote involvement.

Synchronous replication does not directly affect read performance on the source array, as reads can usually be served from local cache or disks without waiting for remote confirmation.

Synchronous remote replication inherently introduces latency to write operations because each write must be committed and acknowledged by the remote array, therefore it always affects write performance on the source array.