SmartSync policies may be throttled to limit system and network impacts. Depending on the workflow requirements of the source and target platforms, consider using the throttling options. For PowerScale-to-PowerScale replication, before you apply additional throttling, consider using a pull policy rather than the traditional push, since this policy offloads impacts to the target cluster.
Bandwidth
Bandwidth throttling is specified for a specific subnet netmask, and a bandwidth limit is specified in bytes using the following command:
isi dm throttling bw-rules create NETMASK –[subnet] --bw-limit=
CPU
SmartSync’s CPU usage is controlled by two parameters, the “Allowed CPU threshold” and the “System CPU load threshold.” The “Allowed CPU threshold” is the percentage of CPU that SmartSync policies can consume. The “System CPU load threshold” is the node’s CPU usage. If the “System CPU load threshold” is reached and the “Allowed CPU threshold” is reached, then SmartSync throttles CPU usage to stay at or below the “Allowed CPU threshold.”
By default, the “Allowed CPU threshold” is 30 percent, and the “System CPU load threshold” is 90 percent. Therefore, if the node’s total CPU reaches 90 percent and if the SmartSync consumption reaches 30 percent of the total CPU, SmartSync throttles its CPU consumption.
Define CPU throttling with the isi dm throttling settings modify command. Use the isi dm throttling settings view command to view the current CPU throttling setting.
To specify the “Allowed CPU threshold,” use the –-allowed-cpu-threshold option. To specify the “System CPU load threshold,” use the --system-cpu-load-threshold command. For each option, specify the new threshold without the percentage sign.
