Overview
Delphix Engine version 2025.3.0.0 introduces a new parameter to implement RMAN RATE parameter when taking a snapshot of an Oracle dSource via the CLI. If this parameter is set, an upper limit will be set for the megabytes per second read rate while taking a snapshot of an Oracle dSource, so that RMAN does not consume excessive disk bandwidth and degrade online performance. If this parameter is not specified, no limit is enforced.
The RMAN RATE parameter is used to limit the database read rate during a backup. This can be useful in situations where Oracle needs to read more blocks than it writes to the backup, typically when performing an incremental backup where Block Change Tracking (BCT) is not used or is ineffective. It is important to note that this is different from the bandwidth limit parameter that controls the I/O rate over the network from the Oracle host to the Delphix Engine and should be used when the goal is to limit the network utilization rather than the RMAN read throughput. The two parameters can be used in conjunction to limit both the read I/O as well as the network throughput.
Prerequisites
None
Command
ssh admin@yourengine
delphix> database
delphix database> select myDatabase
delphix database 'myDatabase'> sync
delphix database 'myDatabase' sync *> set rmanRateInMB=10
delphix database 'myDatabase' sync *> commit