Parallel data transfer configuration parameters for AFM-based DR

All parallel data transfer parameters do not need the gateway node daemon recycle for the new value to take effect.

The parameters in the following table can be used at the cache cluster for tuning parallel data transfer:

Table 1. Configuration parameters at cache for parallel data transfer
AFM configuration parameter	Unit	Description	Mode on AFM DR
afmNumFlushThreads	Whole number	Defines the number of threads used on each gateway to synchronize updates to the home cluster. The default value is 4, which is sufficient for most installations. The current maximum value is 1024, which is too high for most installations. Do not set this parameter to an extreme value.	primary
afmNumWriteThreads	Whole number	Defines the number of threads used on each participating gateway node during a parallel write. The default value of this parameter is 1. That is, one writer thread is active on every gateway node for each big write operation qualifying for splitting as per the parallel write threshold value.	primary
afmParallelWriteChunkSize	bytes	Defines the minimum chunk size of the write that needs to be distributed among the gateway nodes during parallel writes.	primary
afmParallelWriteThreshold	MB	Defines the threshold beyond which parallel writes become effective. Writes are split into chunks when file size exceeds this threshold value. Values are in MB. The default value is 1024 MB.	primary
afmHardMemThreshold	bytes	Sets the maximum memory that AFM can use on each gateway node for handling queues. After this limit is reached, queues might not be handled on this gateway node due to lack of sufficient memory. Filesets belonging to this gateway node might go to a 'Dropped' state, depending on the activity. Exceeding the limit can occur if the cache cluster is disconnected for an extended time or if the connection with the home cluster has low bandwidth and therefore a lot of pending requests are accumulated in the queue. After the value of this parameter is changed, a gateway node daemon recycle is required for the new value to take effect.

Table 2. Configuration parameters at cache for parallel data transfer - valid values
AFM configuration parameter	Valid values	Default value	Tunable at the cluster level	Tunable at the fileset level
afmNumFlushThreads	1 - 1024	4	No	Yes
afmNumWriteThreads	1 - 64	1	Yes	Yes
afmParallelWriteChunkSize	0 - 2147483647	128	Yes	Yes
afmParallelWriteThreshold	0 - 2147483647	1024	Yes	Yes
afmHardMemThreshold		5 G	Yes	No