This section describes the storage optimization module options. This section includes the following topics:

RiOS v6.0.1 or later includes storage optimization modules for the FCIP and SRDF protocols. These modules provide enhanced data reduction capabilities. The modules use explicit knowledge of where protocol headers appear in the storage replication data stream to separate out headers from the payload data that was written to storage. In absence of a module, these headers represent an interruption to the network stream, reducing the ability of RiOS SDR to match on large, contiguous data patterns.

The modules must be configured based on the types of storage replication traffic present in the network environment. The following sections describe these options and when they would be applied.

This section describes the storage optimization for FCIP and how to configure it. This section includes the following topics:

The module for FCIP is appropriate for environments using storage technology that originates traffic as fibre channel (FC) and then uses a Cisco MDS gateway to convert the FC traffic to TCP for WAN transport.

For information about storage technologies that originate traffic via FC, see Storage Area Network Replication. For configuration best-practice details for Cisco MDS deployments, see Best Practices for SAN Replication Using Cisco MDS FCIP.

All configuration for FCIP must be applied on the SteelHead closest to the FCIP gateway that opens the FCIP TCP connection by sending the initial SYN packet. If you are unsure which gateway initiates the SYN in your environment, Riverbed recommends that you apply the module configuration to the SteelHeads on both ends of the WAN.

By default, the FCIP module is disabled. When only the base FCIP module has been enabled, all traffic on the well-known FCIP TCP destination ports 3225, 3226, 3227, and 3228 are directed through the module for enhanced FCIP header isolation. In most environments, no further FCIP module configuration is required beyond enabling the base module.

The Current Connections report shows optimized connections with the App label for each connection shown as FCIP, if the base FCIP module is enabled and connections are established. If the report shows an application of a connection as TCP, the module is not used and you must check the configuration.

An environment that has RF-originated SRDF traffic between VMAX arrays requires additional configuration beyond enabling the FCIP base module. Specifically, the SRDF protocol implementation used to replicate between two VMAX arrays uses an additional Data Integrity Field (DIF) header, which further interrupts the data stream. For Open Systems environments (such as Windows and UNIX/Linux), the DIF header is injected into the data stream after every 512 bytes of storage data. For IBM iSeries (AS/400) environments, the DIF header is injected after every 520 bytes. Do not add a module rule isolating DIF headers in mainframe environments, because SRDF environments that replicate mainframe traffic do not currently include DIF headers.

If your environment includes RF-originated SRDF traffic between VMAX arrays, the module can be configured to look for DIF headers.

For example, if the only FCIP traffic in your environment is RF-originated SRDF between VMAX arrays, you can allow for isolation of DIF headers on all FCIP traffic by modifying the default rule as follows:

Environments that have a mix of VMAX-to-VMAX RF-originated SRDF traffic along with other FCIP traffic require additional configuration, because SteelHeads must be informed where DIF headers are expected. This configuration is made based on IP addresses of the FCIP gateways. In such a mixed environment, SAN zoning needs to be applied to ensure that DIF and non-DIF traffic are not carried within the same FCIP tunnel.

Assume your environment consists mostly of regular, non-DIF FCIP traffic but also some RF-originated SRDF between a pair of VMAX arrays. Assume a pair of FCIP gateways are configured with a tunnel to carry the traffic between these VMAX arrays, and that the source IP address of the tunnel is 10.0.0.1 and destination IP is 10.5.5.1. The preexisting default rule tells the module not to expect DIF headers on FCIP traffic. This setting allows for correct handling of the all the non-VMAX FCIP. To obtain the desired configuration, enter the following command to override the default behavior and perform DIF header isolation on the FCIP tunnel carrying the VMAX-to-VMAX SRDF traffic:

When configured, the FCIP module looks for a DIF header after every 512 bytes of storage data, which is typical for an Open Systems environment. If your environment uses IBM iSeries (AS/400) hosts, use the dif-blocksize to inform the module to look for a DIF header after every 520 bytes of storage data. Enter the following command to modify the default rule to look for DIF headers on all FCIP traffic in a VMAX-based, IBM iSeries (AS/400) environment:

You can display each rule currently configured, whether DIF header isolation is enabled or disabled for that rule, and how much storage data is expected before each DIF header in traffic matching that rule.

This section describes the storage optimization for SRDF and how to configure it. This section includes the following topics:

The module for SRDF is appropriate for environments using EMC's Symmetrix Remote Data Facility (SRDF) with DMX and VMAX storage arrays when the traffic is originated directly from Gigabit Ethernet ports on the arrays (also referred to as RE ports). When in this configuration, the SRDF traffic appears on the network immediately as TCP. The SRDF protocol injects headers into the data stream; these headers interrupt the continuity of SteelHead Data Reduction (SDR). The SRDF module removes these headers from the data stream before performing data reduction, and then reinjects them before sending data to the receiving EMC Symmetrix. In addition, the SRDF module automatically disables native EMC SRDF compression for SRDF transfers, which prevents the need for a BIN file change to disable compression. In the event of a SteelHead or network failure, the Symmetrix arrays fall back on native compression instead of transmitting at uncompressed bandwidth rates.

All configuration for SRDF must be applied on the SteelHead closest to the Symmetrix array that opens the SRDF TCP connection by sending the initial SYN packet. If you are unsure which array initiates the SYN in your environment, Riverbed recommends that you apply module configuration to the SteelHeads on both ends of the WAN.

By default, the SRDF module is disabled. When only the base SRDF module has been enabled, all traffic on the well-known SRDF TCP destination port 1748 is directed through the module for enhanced header isolation. In most environments using SRDF only between DMX arrays or VMAX-to-DMX, no further SRDF module configuration is required beyond enabling the base module.

You can see whether the module is currently enabled or disabled, and on which TCP ports the module is looking for SRDF traffic.

The Current Connections report shows optimized connections with the App label for each connection shown as SRDF, if the base SRDF module is enabled and connections are established. If the report shows a connection's App as TCP, the module is not used and the configuration must be checked.

For Symmetrix VMAX running Enginuity microcode levels newer than 5874, you do not need to configure SRDF module rules (for details, see Configuring SRDF Selective Optimization). For Symmetrix VMAX running Enginuity level 5874 or older, configure SRDF module rules as described in the following section.

To detect Symmetrix microcode level for Open Systems-connected Symmetrix, use the symcfg command in EMC's Solutions Enabler software. Solutions Enabler is EMC software is typically used for managing Symmetrix storage arrays. The following is example output:

An environment that has RE-originated SRDF traffic between VMAX arrays requires additional configuration beyond enabling the base module. Specifically, the SRDF protocol implementation used to replicate between two VMAX arrays employs an additional Data Integrity Field (DIF) header, which further interrupts the data stream. For Open Systems environments (such as Windows and UNIX/Linux), the DIF header is injected into the data stream after every 512 bytes of storage data. For IBM iSeries (AS/400) environments the DIF header is injected after every 520 bytes. Do not add a module rule isolating DIF headers in mainframe environments, because SRDF environments that replicate mainframe traffic do not currently include DIF headers.

If your environment includes RE-originated SRDF traffic between VMAX arrays, the module can be configured to look for DIF headers.

For example, if the only RE-originated SRDF traffic in your environment is between VMAX arrays, you can allow for isolation of DIF headers on all SRDF traffic by modifying the default rule as follows:

Environments that have a mix of VMAX-to-VMAX and DMX-based SRDF traffic require additional configuration, because SteelHeads must be informed where DIF headers are expected. This configuration is made based on RE port IP addresses.

Assume your environment contained RE-originated SRDF traffic mostly between DMX arrays but also some between a pair of VMAX arrays. Assume the VMAX array in the primary location had RE ports of IP addresses 10.0.0.1 and 10.0.0.2 and the VMAX array in the secondary location had RE ports of IP addresses 10.5.5.1 and 10.5.5.2. The preexisting default rule tells the module not to expect DIF headers on all RE-originated SRDF traffic. This allows for correct handling of the main DMX-based SRDF traffic. To obtain the desired configuration, enter the following commands to override the default behavior and perform DIF header isolation on the VMAX SRDF connections:

When configured, the SRDF module looks for a DIF header after every 512 bytes of storage data, which is typical for an Open Systems environment. If your environment uses IBM iSeries (AS/400) hosts, rules that use the dif-blocksize to inform the module to look for a DIF header after every 520 bytes of storage data. Enter the following command to modify the default rule to look for DIF headers on all SRDF traffic in a

VMAX-based, IBM iSeries (AS/400) environment:

This shows each rule currently configured, whether DIF header isolation is enabled or disabled for that rule, and how much storage data is expected before each DIF header in traffic matching that rule.

RiOS v6.1.2 or later feature selective optimization. Selective optimization is the ability to provide different types of optimization to different RDF Groups, and allows you to tune for the best optimization setting for each RDF group to maximize the SteelHead usability. Selective optimization also depends on Symmetrix VMAX Enginuity microcode levels newer than 5874.

Consider an example with three types of data:

In this example, assign LZ-only compression to the Oracle logs, no optimization to the encrypted check images, and default SDR to the virtual machine images. To assign these levels of optimization, configure the SteelHead to associate specific RE port IP addresses with specific Symmetrix arrays, and then assign rules to specific RDF groups for different optimization policies.

RDF_GROUP in RiOS is specified as a decimal number; however some EMC utilities report RDF group numbers in hexadecimal.

When you have Symmetrix arrays serving Open Systems hosts, and you are using EMC Solutions Enabler, RDF group numbers are reported in decimal—ranging from 1 to 255. By default, this is how RDF_GROUP is entered in RiOS and shown in reports. For mainframe-attached Symmetrix arrays, tools report RDF group numbers in hexadecimal, starting from 0. Use the following command for SteelHeads serving only mainframe-attached Symmetrix arrays, and you want the representation of RDF_GROUP to be in the range 0 to 254:

In the example of three RDF groups (assuming a SYMMID of 123), enter the following commands:

The following shows an example of output:

For details of these commands, commands to show the current srdf configuration (show protocol srdf symm id), and to show reduction statistics for all or specific SYMMIDs (show protocol srdf symm stats), see the Riverbed Command-Line Interface Reference Manual.

In RiOS v7.0 or later, you can report SRDF statistics on a per-RDF-group basis. The following command displays statistics for all RDF groups being optimized:

This command shows statistics from a specific Symmetrix machine (indicated by symm_id):

This command shows statistics from a specific RDF group (indicated by rdf group):

To view these reports, open the Management Console, and choose Reports > Optimization: SRDF.