Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

SRDF/Metro

HYPERMAX OS 5977.691.684 and Solutions Enabler 8.1 introduced SRDF/Metro which is a significant departure from traditional SRDF.

In SRDF/Metro configurations, R2 devices on arrays can be Read/Write accessible to hosts. SRDF/Metro R2 devices acquire the federated personality of the primary R1 device (such as geometry and device WWN). This federated personality of the R2 device causes the R1 and R2 devices to appear to host(s) as a single virtual device across both SRDF paired arrays.

By default, an SRDF/Metro configuration uses a Witness to determine which side of the SRDF device pair remains R/W accessible to the host or hosts in the event of link or other failures. The witness can be another array (an array Witness) or virtual Witness (vWitness).

SRDF/Metro Operations provides more information on SRDF/Metro and how to manage it.

Multi-cores, multi-ports per director

In Enginuity 5876, all front-end emulations supported up to two ports. Multiple front-end emulations could exist on the same director board, providing additional host connectivity, but all such front-end directors were limited to one or two physical ports.

VMAX3 and VMAX All Flash arrays running HYPERMAX OS and Solutions Enabler 8.0.1 and later support a single front-end emulation of each type (sych as FA and EF) for each director, but each of these emulations supports a variable number of physical ports. Both the SRDF Gigabit Ethernet (RE) and SRDF Fibre Channel (RF) emulations can use any port on the director. The relationship between the SRDF emulation and resources on a director is configurable:

• 1 director for 1 or multiple CPU cores for 1 or multiple ports

Connectivity is not bound to a fixed number of CPU cores. You can change the amount of connectivity without changing CPU power.

The SRDF emulation supports up to 16 front-end ports per director (4 front-end modules per director), any or all of which can be used by SRDF. Both the SRDF Gigabit Ethernet and SRDF Fibre Channel emulations can use any port.

When you create an SRDF group on VMAX3 arrays and VMAX All Flash arrays, select both the director AND the ports for the SRDF emulation to use on each side.

Syntax

Use the symrdf addgrp command to create a SRDF group.

symrdf addgrp -sid SID  -label GrpLabel -rdfg GrpNum [-noprompt] 
    [-i Interval] [-c Count]
        ...........
        -dir Dir:Port,Dir:Port,...
        -remote_rdfg GrpNum 
        -remote_sid SID -remote_dir Dir:Port,Dir:Port,...
        -fibre | -gige | -farpoint
        -link_domino {on|off}
        -remote_link_domino
        -auto_link_recovery {on|off}
        -remote_auto_link_recovery
        -link_limbo Secs -rem_link_limbo Secs
        -witness
								-vasa -async
								-sc_name <SC_Name> -remote_sc_name <SC_Name>

Required options

-sid SID

The ID of the array where the group is added.

-label GrpLabel

A label for a dynamic SRDF group.

-rdfg GrpNum

An SRDF group number. Valid values are 1 - 250.

-dir Dir:Port, Dir:Port

A comma-separated list one or more ports on a local director to be added to the group.

-remote_dir Dir:Port, Dir:Port

A comma-separated list one or more ports on a remote director to be added to the group.

-remote_rdfg GrpNum

The SRDF group number on the remote array.

-remote_sid SID

The ID of the remote array.

Optional options

-vasa

Specifies that the SRDF group being created is a VASA SRDF group that can be used by VASA remote replication. The following options cannot be used when specifying -vasa -async:

• -link_domino
• -remote_link_domino
• -autolink_recovery
• -remote_autolink_recovery
• -witness

-async

Identifies that the VASA SRDF group being created should be created in Asynchronous mode.

NOTE:This option is only allowed when the option -vasa is specified.

-sc_name

Specifies the storage container name associated with the SID.

NOTE:This option is only allowed when the option -vasa is specified.

-remote_sc_name

Specifies the storage container name associated with the remote SID.

NOTE:This option is only allowed when the option -vasa is specified.

-fibre | -gige | -farpoint

The communication protocol for the group: Fibre Channel, Gigabit Ethernet, or FarPoint.

-link_domino {on|off}

Switches link domino mode on or off (see Domino mode).

-remote_link_domino {on|off}

Switches link domino mode on or off on the remote array.

-auto_link_recovery {on|off}

Switches autolink recovery on or off on the local array (see Autolink recovery).

-remote_auto_link_recovery

Switches autolink recovery on or off on the remote array.

-link_limbo 0 - 120

Sets the value of the link limbo timer for the local array (see Link limbo).

-rem_link_limbo 0 - 120

Sets the value of the link limbo timer for the remote array.

-witness

Identifies the SRDF group as a Witness group.

Requirements

The following are requirements for adding a dynamic SRDF group:

• The dynamic_rdf parameter must be enabled.
• The local or remote array must not be in the symavoid file.

• You can perform multiple operations (addgrp, modifygrp, removegrp), but each operation must complete before starting the next.
• Always specify a group label when adding a dynamic group.

Example - HYPERMAX OS

Arrays running HYPERMAX OS support multiple ports per director. You specify both the director ID and the port number when specifying the local and remote ports to add to the new SRDF group.

To specify 3 ports on each array:

symrdf addgrp -label new_group -rdfg 39 -remote_rdfg 49
-dir 2f:11,1f:12,2h:3-remote_dir 1h:2,2e:3,2f:12 
-sid 000197100001 -remote_sid 000197100228 -nop

Example - Enginuity 5876

Arrays running Enginuity 5876 support a single port per director. Specify only the director ID when specifying the local and remote ports to add to the new SRDF group. For example:

symrdf addgrp -label new_group -rdfg 39 -remote_rdfg 49
-dir 2f -remote_dir 1h -sid 000195700001
-remote_sid 000195700228 -nop

Example - Mixed configurations

When one array in an SRDF configuration is running HYPERMAX OS, and one array is running Enginuity 5876, specify only the director ID on the array running 5876, and specify both the director ID and port number on the array running HYPERMAX OS. For example:

symrdf addgrp -label new_group -rdfg 39 -remote_rdfg 49
-dir 3h:12 -remote_dir 5f -sid 000197100001
-remote_sid 000195700228 -nop