Policy Pages Reference : Optimization Policy Settings : Performance
  
Performance
You enable settings to improve network and RiOS data store performance in the Performance page.
For details about performance optimization, see the SteelHead Management Console User’s Guide for SteelHead CX.
Data Store
Complete the configuration as described in this table.
Control
Description
Segment Replacement Policy
 
•  Riverbed LRU - Replaces the least recently used data in the RiOS data store, which improves hit rates when the data in the RiOS data store are not equally used. This is the default setting.
•  FIFO - Replaces data in the order received (first in, first out).
Adaptive Data Streamlining
The adaptive data streamlining mode monitors and controls the different resources available on the SteelHead and adapts the utilization of these system resources to optimize LAN throughput. Changing the default setting is optional; Riverbed recommends you select another setting only with guidance from Riverbed Support or the Riverbed Sales Team.
Generally, the default setting provides the most data reduction. When choosing an adaptive streamlining mode for your network, contact Riverbed Support to help you evaluate the setting based on:
•  the amount of data replication your SteelHead is processing.
•  the type of data being processed and its effects on disk throughput on the SteelHeads.
•  your primary goal for the project, which could be maximum data reduction or maximum throughput. Even when your primary goal is maximum throughput you can still achieve high data reduction.
Complete the configuration as described in this table.
Setting
Description
Default
This setting is enabled by default and works for most implementations. The default setting:
•  Provides the most data reduction.
•  Reduces random disk seeks and improves disk throughput by discarding very small data margin segments that are no longer necessary. This margin segment elimination (MSE) process provides network-based disk defragmentation.
•  Writes large page clusters.
•  Monitors the disk write I/O response time to provide more throughput.
SDR-Adaptive
Legacy - Includes the default settings and also:
•  Balances writes and reads.
•  Monitors both read and write disk I/O response, and CPU load. Based on statistical trends, can employ a blend of disk-based and non-disk-based data reduction techniques to enable sustained throughput during periods of disk/CPU-intensive workloads.
Use caution with the SDR-Adaptive Legacy setting, particularly when you are optimizing CIFS or NFS with prepopulation. Contact Riverbed Support for more information.
Advanced - Maximizes LAN-side throughput dynamically under different data workloads. This switching mechanism is governed with a throughput and bandwidth reduction goal using the available WAN bandwidth. Both SteelHeads must be running RiOS 6.0.x or later.
Upgrade notes: If you have enabled SDR-Adaptive prior to upgrading to RiOS 6.0, the default setting is SDR-Adaptive Legacy.
If you did not change the SDR-Adaptive setting prior to upgrading to RiOS 6.0, the default setting is SDR-Adaptive Advanced.
SDR-M
Performs data reduction entirely in memory, which prevents the SteelHead from reading and writing to and from the disk. Enabling this option can yield high LAN-side throughput because it eliminates all disk latency. This is typically the preferred configuration mode for SAN replication environments.
SDR-M is most efficient when used between two identical high-end SteelHead models: for example, 6050 - 6050. When used between two different SteelHead models, the smaller model limits the performance.
After enabling SDR-M on both the client-side and the server-side SteelHeads, restart both SteelHeads to avoid performance degradation.
Note: You cannot use peer RiOS data store synchronization with SDR-M.
CPU Settings
Use the CPU settings to balance throughput with the amount of data reduction and balance the connection load. The CPU settings are useful with high-traffic loads to scale back compression, increase throughput, and maximize Long Fat Network (LFN) utilization.
Complete the configuration as described in this table.
Setting
Description
Compression Level
Specifies the relative trade-off of data compression for LAN throughput speed. Generally, a lower number provides faster throughput and slightly less data reduction.
Select a RiOS data store compression value of 1 (minimum compression, uses less CPU) through 9 (maximum compression, uses more CPU) from the drop-down list. The default value corresponds to level 6.
Riverbed recommends setting the compression level to 1 in high-throughput environments such as data center-to-data center replication.
Adaptive Compression
Detects LZ data compression performance for a connection dynamically and turns it off (sets the compression level to 0) momentarily if it is not achieving optimal results. Improves end-to-end throughput over the LAN by maximizing the WAN throughput. By default, this setting is disabled.
Multi-Core Balancing
Enables multicore balancing, which ensures better distribution of workload across all CPUs, thereby maximizing throughput by keeping all CPUs busy. Core balancing is useful when handling a small number of high-throughput connections (approximately 25 or less). By default, this setting is disabled and should be enabled only after careful consideration and consulting with Sales Engineering or Riverbed Support.