� More impact on server
� Impact on application
performance depends upon:
Data � File system and software used
� Speed and bandwidth of
� Whether servers and arrays are
local or remote
Here the host writes to the primary, and to the secondary, the primary
acknowledges, the secondary acknowledges.
If it’s synchronous it waits for both acknowledgements.
If it’s asynchronous the application will move on after the primary
acknowledges, but it still waits for the secondary before clearing out its
Obviously if we use host based replication this will now work with any storage
vendor because as long as we can see the logical units we can mirror
How much impact on the application server depends on the file system, the
software, the infrastructure and the latency.