Configuring Dynamic SRDF Using SYMCLI

 

Topic

Managing SRDF

Selections

Select SRDF management tool: Managing SRDF using Solutions Enabler SYMCLI

Select SRDF using SYMCLI task: Managing Dynamic SRDF

Select a Dynnamic SRDF task: Configure Dynamic SRDF

 

 

Contents

Configuring dynamic SRDF. 3

Overview  3

About this procedure. 3

Task 1:  Enable dynamic SRDF on the array. 3

Task 2:  Create dynamic SRDF devices. 4

Task 3:  Verify the new devices are created and dynamic RDF enabled. 4

Task 4:  View host connections. 5

Task 5:  Find available addresses for the director and port 5

Task 6:  Map the new dynamic devices. 6

Task 7:  Mask the new dynamic devices. 6

Task 8:  Update the SYMAPI database. 7

Task 9:  Create and map devices on the remotely attached Symmetrix. 7

Creating dynamic SRDF groups. 7

About this procedure. 7

Task 10:......................................... Identify RDF connections between source and target arrays. 8

Task 11:.............................................................................. Add a dynamic SRDF device group. 8

Task 12:................................................................................................. Enable dynamic SRDF. 10

Task 13:...................................................................... Add dynamic pairs to the dynamic group. 10

Task 14:.............................................................................. Set the mode to adaptive copy disk. 11

Task 15:......................................................................... Establish the device pairs in the group. 12

Task 16:..................................................................................................... Set the group mode. 13

 


 

Configuring dynamic SRDF

Overview

Dynamic SRDF enables you to create, delete, swap and manage SRDF pairs while the Symmetrix array is in operation.

Dynamic SRDF enables you to establish SRDF device pairs from nonconfigured SRDF devices, and then synchronize and manage them in the same way as configured SRDF pairs.

Dynamic SRDF pairing requires an SRDF license and the dynamic SRDF configuration state of the Symmetrix array must be enabled.

You should be familiar with the concepts of SRDF, and have some experience using Solutions Enabler SYMCLI commands before attempting this procedure.

About this procedure

·    This procedure was created using a version of Solutions Enabler earlier than 7.4.

IMPORTANT:   The dynamic_rdf option became obsolete in Solutions Enabler 7.4.

·    This procedure describes the following tasks:

·    Enable dynamic SRDF on the Symmetrix

·    Create, map and mask dynamic SRDF devices

·    Create and establish dynamic SRDF device pairs

·    Build a dynamic device group

 

·    This procedure is based on content in the following guides:

·     EMC Solutions Enabler Symmetrix Array Controls CLI Product Guide

·    EMC Solutions Enabler Symmetrix SRDF Family CLI Product Guide

·    SRDF/A and SRDF/A Multi-Session Consistency on UNIX and Windows EMC Engineering Solutions Guide

 

You can download the guides from EMC Online Support (registration required): https://support.EMC.com.

Task 1:     Enable dynamic SRDF on the array

   1. [   ]    Type the symcfg list –v command to display detailed information about attached arrays.

symconfigure list –v

 

View the output to check if the Dynamic RDF Configuration State is set to Enabled.

The next step varies depending on whether Dynamic RDF Configuration State is set to Enabled.

If Dynamic RDF Configuration State is set to Disabled, proceed to Step 0.

If Dynamic RDF Configuration State is set to Enabled, skip to Task 2: on page 4.

   2. [   ]    Use a text editor (NotePad, vi) to create a text file containing the following line:

set symmetrix dynamic_rdf=enabled;

 

   3. [   ]    Type the symconfigure –sid SID commit –file FileName command to enable Dynamic SRDF on the local array, where:

-sid SID is the Symmetrix ID of the local array

-file FileName is the name of the text file created in Step 2. [   ].

To enable dynamic SRDF on the local array using text file named set_sym.cmd:

symconfigure –sid 605 commit –file set_sym.cmd

 

   4. [   ]    You must enable dynamic SRDF on the remote array.

Repeat Step 3. [   ] from a host connected to the remote array to enable dynamic SRDF on the remote array.

Task 2:     Create dynamic SRDF devices

                       

   1. [   ]    Use a text editor (NotePad, vi) to create a text file containing the following line:

create dev, count=n, size=n, emulation=EmulationType, config=DevConfig, dynamic_capability=dyn_rdf;

In the following example, the vi editor creates a text file named create_std.cmd to create:

·        Six new 2-Way-Mir devices

·        Each device will have 1100 cylinders

·        Emulation type is fba (Fibre Channel director)

·        The devices can be dynamically converted to an R1 or an R2 device.

 

vi create_std.cmd

create dev, count=6, size=1100m, emulation=fba, config=2-Way-Mir, dynamic_capability=dyn_rdf;

 

   2. [   ]    Use the symconfigure –sid SID commit –file FileName command to execute the command file and initiate the processing to create 6 new standard devices as RDF-capable.

To create new devices on Symmetrix 605 using the parameters in text file create_std.cmd:

symconfigure –sid 605 commit –file create_std.cmd

 

Task 3:     Verify the new devices are created and dynamic RDF enabled

                       

   1. [   ]    Type the symdev –sid SID list command to verify that the new devices were created.

For example:

symdev –sid 605 list

 

   2. [   ]    Examine the output for a list of the new 2-Way-Mir devices and their assigned devices numbers.

   3. [   ]    Type the symdev –sid SID list –dynamic command to display all devices that are configured as dynamic RDF capable.

For example:

symdev –sid 605 list –dynamic

 

Note:  To show only R1 or R2 devices, include the –r1 or –r2 option in the command line.

 

   4. [   ]    Type the symdev –sid SID show DeviceNum command to display device attributes for at least one of the new devices.

To display device 0091 on Symmetrix 605:

symdev -sid 605 show 0091

   5. [   ]    Check the output to confirm that devices have been set to:

Dynamic RDF Capability: RDF1_OR_RDF2_Capable

Task 4:     View host connections

                       

   1. [   ]    Type the symcfg –sid SID list – connections command to display the connections from this host to the Symmetrix array.

To display the connections from this host to Symmetrix 605:

symcfg –sid 605 list –connections

 

   2. [   ]    Note which front-end director (for example, FA-4A) your host uses to reach the Symmetrix array.

Task 5:     Find available addresses for the director and port

                       

   1. [   ]    Type the symcfg –sid SID list –sa Dir# -p Port# -addresses –available command to list the available addresses for the specified director and port.

To display availalble addresses for front-end director 04A port 0 on Symmetrix 605:

symcfg –sid 605 list –sa 04A –p 0 -addresses –available

 

The output displays:

·        VBUS, TID and LUN addresses associated with front-end director 04A, port 0,

·        Indicates the next available address in the run.

 

In the following output, there is a large run of available LUN addresses between 004 and 060:

 

Symmetrix ID: 000000005605 (Local)

 

           Director                 Device Name       Attr     Address  

    ---------------------- -------------------------- ---- --------------

    Ident   Symbolic  Port Sym   Physical                  VBUS  TID  LUN

    ------  --------  ---- ----  --------------------      ----  ---  ---

 

    FA-4A   04A       0    -     AVAILABLE                    0    0  000 *

                           0001  /dev/rdsk/c1t0d1s2           0    0  001

                           0002  /dev/rdsk/c1t0d2s2           0    0  002

                           0003  /dev/rdsk/c1t0d3s2           0    0  003

                           -     AVAILABLE                    0    0  004 *

                           0040  /dev/rdsk/c1t0d96s2          0    0  060

                           0041  /dev/rdsk/c1t0d97s2          0    0  061

                           0042  /dev/rdsk/c1t0d98s2          0    0  062

                           0043  /dev/rdsk/c1t0d99s2          0    0  063

                           -     AVAILABLE                    0    0  064 *

 

 

Legend for Available address:

 (*): The VBUS, TID, LUN address values represent a gap in the address

      assignments or are the next available address in the run

 

   2. [   ]    Select LUN values for the new devices.

IMPORTANT:   Consider the LUN conventions for your host platform.

In this example, there is a large run of available LUN addresses between 004 and 060.

The next task uses LUN addresses 004 through 009 for mapping the six new devices.

Task 6:     Map the new dynamic devices

                       

   1. [   ]    Use a text editor (NotePad, vi) to create a text file containing the mapping instructions for the new devices.

Map one device per line, using the following format:

map dev DevNum to dir PortNum, lun=LUNAddress;

In the following example, the vi editor creates text file map_dyn_devices.cmd:

vi map_dyn_devices.cmd

map dev 091 to dir 04A:0, lun=004;

map dev 092 to dir 04A:0, lun=005;

map dev 093 to dir 04A:0, lun=006;

map dev 094 to dir 04A:0, lun=007;

map dev 095 to dir 04A:0, lun=008;

map dev 096 to dir 04A:0, lun=009;

 

   2. [   ]    Type the symconfigure –sid SID commit –file FileName command to map the new devices.

To map the 6 devices listed in text file map_dyn_devices.cmd on Symmetrix 605:

symconfigure –sid 605 commit –file map_dyn_devices.cmd

 

Task 7:     Mask the new dynamic devices

                       

   1. [   ]    Type the symmask command to mask the dynamic devices to a specified HBA/director-port channel. The syntax for the command:

symmask -sid SymmID

-wwn WorldWideName|-awwn aliasWorldWideName|-iscsi iSCSIName |-aiscsi aliasiSCSIName

add devs startSymDevname:endSymDevname|SymDevname|SymDevname,,,...\

-dir DirNum -p PortNum

To mask devices 091 through 096 on Symmetrix 605 for access to HBA 10:00:00:00:c9:40:a8:a3 using director 04A, port 0:

 

symmask -sid 605 –wwn 10000000c940a8a3 add devs 091,092,093,094,095,096 -dir 04A -p 0

 

Note:  If the devices are not addressed to the specified FA, a warning message is displayed.

A message is displayed if the devices are already assigned in the database to any WWN. To turn off this functionality, use the -noprompt option.

   2. [   ]    Activate the configuration by performing the following:

·        Refresh (symmask refresh)

·        Back up the database (symmaskdb backup), and

·        Reboot the affected hosts.

 

Note:  When you reboot a host, you must run symcfg discover on all the Symmetrix devices and refresh the SYMAPI database.

   3. [   ]    Type the symmaskdb –sid SID list assignment –dev StartDev:EndDev command to display whether the masking succeeded.

To verify that the masking for devices 91 through 96 succeeded:

 

symmaskdb -sid 605 list assignment –dev 91:96

 

The display lists the host WWNs and shows the devices masked to the corresponding HBAs.

Alternatively, type the symmaskdb –sid SID list devs –wwn WorldWideName command to display the masking for the specified World Wide Name.

To display the masking for WWN 10000000c940a8a3:

symmaskdb -sid 605 list devs –wwn 10000000c940a8a3

 

Task 8:     Update the SYMAPI database

                       

   1. [   ]    Type the symcfg discover command to update the SYMAPI database.

symcfg discover

 

Note:  This operation may take a few minutes to complete.

   2. [   ]    Type the sympd –sid SID list command to verify that the newly mapped devices are visible to the host.

To display SID 605:

sympd –sid 605 list

 

Task 9:     Create and map devices on the remotely attached Symmetrix

                       

   1. [   ]    Repeat Task 1: through Task 8: to create the same number of dynamic devices on the remotely attached Symmetrix.

Note:   You must perform the steps to mask devices (Task 7: and Task 8:) from a host that is local to the remote Symmetrix.

Your dynamic R1 and R2 devices are now created mapped and masked.

The tasks to create, pair, and establish SRDF pairs are described in Creating dynamic SRDF groups.

Creating dynamic SRDF groups

About this procedure

·    This procedure is a continuation of “Configuring dynamic SRDF using the SYMCLI”.

·    This procedure is based on content in the following guides

·    EMC Solutions Enabler Symmetrix Array Controls CLI Product Guide

·    EMC Solutions Enabler Symmetrix SRDF Family CLI Product Guide

You can download the guides from EMC Online Support (registration required): https://support.EMC.com.

Task 10:  Identify RDF connections between source and target arrays

                       

   1. [   ]    From the SYMCLI prompt, type the symcfg list command to display the local and remote Symmertrix visible to this host.

symcfg list

 

   2. [   ]    Type the symcfg list –ra all –switched command to display the the local and remote Symmetrix arrays, their RDF directors, and RA groups connected in the open RDF switch fabric.

symcfg list -ra all -switched

 

   3. [   ]    Type the symcfg list –sid SID –ra all –switched command twice to display RDF directors for the local and remote arrays.

To display RDF directors on Symmetrix 709 and 774:

symcfg –sid 709 list –ra all –switched

 

symcfg –sid 774 list –ra all –switched

 

   4. [   ]    Examine the output for both local and remote Symmetrix arrays to identify the best RDF connection between the two arrays.

Best practice: Choose ports that are lightly populated for the RDF dynamic group assignment.

Task 11:  Add a dynamic SRDF device group

                       

   1. [   ]    Type the symcfg list –sid SID –rdfg all command twice to display the SRDF groups already configured on the local and remote arrays.

To display existing SRDF groups on Symmetrix 709 and 774:

symcfg list –sid 709 –rdfg all

 

symcfg list –sid 774 –rdfg all

 

   2. [   ]    Select a name for the new SRDF group that is NOT already in use.

   3. [   ]    Type the symrdf addgrp command to add a dynamic SRDF group.

The syntax for the command is:

symrdf addgrp

Required arguments:

-label GrpLabel – Label for the dynamic SRDF group.

-rdfg GrpNum – Group number for the SRDF group on the local array. This number must NOT be in use on the local array.

-sid SymmID Symmetrix ID of the local array.

-dir Dir Director on the local array.

-remote_rdfg GrpNum – Group number for the SRDF group on the remote array. This number must NOT be in use on the remote array.

-remote_sid SymmID - Symmetrix ID of the remote array.

-remote_dir Dir - Director on the remote array.

-fibre | -gige | -farpoint – Protocol connecting the local and remote arrays:

Fibre Channel, Gigabit Ethernet, or FarPoint.

Optional arguments:

Note:  Link limbo may be set after the group is created using the symrdf set command. The auto link recovery and link domino parameters can only be set at group creation time

-link_domino Enabled | DisabledWhen enabled, if the last available link in the SRDF group fails, the next host write to any R1 device in the SRDF group causes all R1 devices in the SRDF group become Not Ready to their hosts. Link domino ensures that data on the source (R1) and the target (R2) devices are always in sync.

The default is disabled.

-remote_link_domino Enabled | Disabled Enables/disables link domino at the remote Symmetrix.

The default is disabled.

 

-auto_link_recovery Enabled | Disabled When enabled, if all SRDF links fail, the Symmetrix array remembers the SRDF states of the affected SRDF devices and can automatically restore the devices to these states once the SRDF links become operational.

Default is disabled.

-remote_auto_link_recovery Enabled | Disabled Enables/disables auto link recover ay the remote Symmetrix.

 

-link_limbo Secs Sets the number of seconds for Enginuity to wait when a down link is detected before updating the link status. If the link status is still not ready after the link limbo time expires, devices are marked not ready to the link.

The default is 10 (seconds).

The range is 0 – 120 (seconds).

-rem_link_limbo Secs Sets link limbo timer for the remote link.

The default is 10 (seconds).

The range is 0 – 120 (seconds).

 

Best practice

·        Specify an RDF group number that is not already in use.

·        Specify the same number for –remote_rdfg and –rdfg.

·        For optimal performance, configure no more than 6 groups per switched Fibre RA.

 

To create local SRDF group 140 with label Group_140 on director 16d on local Symmetrix 709, remote SRDF group 140 on director 16d on remote Symmetrix 774, using the Fibre Channel protocol:

symrdf addgrp –label Group_140 –fibre –sid 709 –rdfg 140 –dir 16d –remote_sid 774 –remote_dir 16d –remote_rdfg 140

 

   4. [   ]    Type the symcfg list –ra all –switched command to verify that the new device group was created.

   5. [   ]    Type the symcfg list –rdfg GrpNum command to display details about the new group.

To display SRDF group 140:

symcfg list –rdfg 140

 

Symmetrix ID : 000190300709

 

                S Y M M E T R I X   R D F   G R O U P S

 

    Local              Remote                   Group               RDFA Info

--------------  ---------------------  -----------------------  -----------------

            LL                                      Flags  Dir  Flags  Cycle

 RA-Grp  (sec)   RA-Grp  SymmID        T    Name     LPDS  Cfg  CSRM   time   Pri

--------------  ---------------------  -----------------------  -----  -----  ---

140 (8B)    10  140 (8B) 000190300774  D Group_140   XX..  F-S  -IS-      30   33

 

Legend:

  ?                 : Unknown

  Group (T)ype      :  S = Static, D = Dynamic

  Director (C)onfig :  F-S = Fibre-Switched, F-H = Fibre-Hub

                       G = GIGE, E = ESCON, T = T3, - = N/A

  Group Flags       :

      Prevent Auto (L)ink Recovery      : X = Enabled, . = Disabled

      Prevent RAs Online Upon (P)ower On: X = Enabled, . = Disabled

      Link (D)omino                     : X = Enabled, . = Disabled

      (S)TAR mode                       : N = Normal, R = Recovery, . = OFF

  RDFA Flags        :

      (C)onsistency : X = Enabled, . = Disabled, - = N/A

      (S)tatus      : A = Active, I = Inactive, - = N/A

      (R)DFA Mode   : S = Single-session, M = MSC, - = N/A

      (M)sc Cleanup : C = MSC Cleanup required, - = N/A

 

Task 12:  Enable dynamic SRDF

                       

   1. [   ]    Use a text editor (NotePad, vi) to create a text file containing the following instruction.

set dev StartDevNum:EndDevtNum attribute=dyn.rdf;

In the following example, the vi editor creates text file set_dev_dyn.cmd:

vi set_dev_dyn.cmd

set dev 0918:091B attribute=dyn.rdf;

 

   2. [   ]    Type the symconfigure –sid SID commit –file FileName command to enable dynamic SRDF on the specified devices on the local Symmetrix.

To enable dynamic SRDF for the devices specified in text file set_dev_dyn.cmd on Symmetrix 709:

symconfigure –sid 709 commit –file set_dev_dyn.cmd

 

   3. [   ]    Repeat Steps 1. [   ] and 2. [   ] on the remote Symmetrix.

For example, to create the text file for the remote Symmetrix:

vi set_dev_dyn.cmd

set dev 072B:072E attribute=dyn.rdf;

 

To enable dynamic SRDF for the specified devices on the remote Symmetrix:

symconfigure –sid 774 commit –file set_dev_dyn.cmd

Task 13:  Add dynamic pairs to the dynamic group

                       

   1. [   ]    Type the symdev –sid SID not_ready DevNum command to set each device on the remote Symmetrix that will be become the R2 of a device pair to the Not_Ready state.

For example:

symdev –sid 774 not_ready 072B

symdev –sid 774 not_ready 072C

symdev –sid 774 not_ready 072D

symdev –sid 774 not_ready 072D

 

   2. [   ]    Use a text editor (NotePad, vi) to create a device file containing two columns, R1 devices in one column, R2 devices in the other column.

·        Add a separate line for each device pair.

·        All devices for one side of the SRDF pair must be in the first column, and all devices for the other side of the SRDF pair must be in the second column. It does not matter which side (R1 or R2) is in which column, because the –type option of the symrdf createpair command determines which columns is R1 or R2.

 

IMPORTANT:   All devices for an SRDF side must be in the same column. That is, all R1 devices must be in either the left or right column, and all R2 devices must be in the other column.

·        Do not use mapped remote devices as R2s without first checking that they are not in use by a remote host.

 

In the following example, the vi editor creates text file create_pair.cmd:

vi create_pair.cmd

0918  072B

0919  072C

091A  072D

091B  072E

 

   3. [   ]    Type the symrdf createpair –file FileName –type r1 –sid SID –rdfg GroupNuminvalidate r2 –g NewDg command to:

·        Create device pairs using the devices listed in the text file and specified Symmetrix and SRDF group

·        Designate devices listed in the left column as R1,

·        Mark the R2 devices in the list for a full device copy once the SRDF pairs are created, and

·        Create a new device group.

 

To create device pairs using devices in text file create_pair.cmd, with the devices in the left column as R1, marking the R2 devices for a full copy, and creating device group dg_rdfg_140:

symrdf createpair –file create_pair.cmd –type r1 –sid 709 –rdfg 140 –invalidate r2 –g dg_rdfg140

 

   4. [   ]    . Type the symrdf –g GroupName ready r2 command to set the R2 devices in the new device group back to the Ready state.

For example:

symrdf –g dg_rdfg140 ready r2 –noprompt

 

Task 14:  Set the mode to adaptive copy disk

                       

   1. [   ]    Type the symrdf –g GroupName set mode acp_disk command to set the mode for the new group to adaptive copy disk.

Best practice

Adaptive copy disk (acp_disk) mode is designed to transfer large amounts of data without loss of performance. Set the mode for the group to adaptive copy disk before establishing the SRDF pairs to avoid I/O latency issues for the host application during the device synchronization.

To set the mode for group dg_rdfg140 to adaptive disk:

symrdf -g dg_rdfg140 set mode acp_disk –noprompt

 

   2. [   ]    Type the symrdf –g GroupName query command to display the group.

To display group dg_rdfg140:

symrdf –g dg_rdfg140 query

 

 

Device Group (DG) Name             : dg_rdfg140

DG's Type                          : RDF1

DG's Symmetrix ID                  : 000190300709    (Microcode Version: 5773)

Remote Symmetrix ID                : 000190300774    (Microcode Version: 5773)

RDF (RA) Group Number              : 140 (8B)

 

 

 

       Source (R1) View                 Target (R2) View     MODES

--------------------------------    ------------------------ ----- ------------

             ST                  LI      ST

Standard      A                   N       A

Logical       T  R1 Inv   R2 Inv  K       T  R1 Inv   R2 Inv       RDF Pair

Device  Dev   E  Tracks   Tracks  S Dev   E  Tracks   Tracks MDA   STATE

-------------------------------- -- ------------------------ ----- ------------

 

DEV001  0918 RW       0    16500 NR 072B WD       0    16500 C.D   Suspended

DEV002  0919 RW       0    16500 NR 072C WD       0    16500 C.D   Suspended

DEV003  091A RW       0    16500 NR 072D WD       0    16500 C.D   Suspended

DEV004  091B RW       0    16500 NR 072E WD       0    16500 C.D   Suspended

 

Total          -------- --------           -------- --------

  Track(s)            0    66000                  0    66000

  MB(s)             0.0   4125.0                0.0   4125.0

 

Legend for MODES:

 

 M(ode of Operation): A = Async, S = Sync, E = Semi-sync, C = Adaptive Copy

 D(omino)           : X = Enabled, . = Disabled

 A(daptive Copy)    : D = Disk Mode, W = WP Mode, . = ACp off

 

   3. [   ]    Check the output to verify that the devices in the group are now in adaptive copy disk mode.

Task 15:  Establish the device pairs in the group

                       

   1. [   ]    (Optionally) type the symqos –g GroupName set RDF priority Priority command to specify how many resources will be used to establish the device pairs.

The establish operation merges the track tables between the R1 and the R2 devices. It then enables the RDF link (makes it enabled for read and write requests) and begins to copy data from the source device to the device which has been designated as invalid.

The establish operation can take a long time. Best practice is to launch establish operations during non-peak hours to minimize the impact of the synchronization traffic over the RDF link.

If there are no non-peak hours of operation, use the the symqos set RDF priority command to minimize the impact of the RDF synchronization for the device group.

The value for priority is an interger from 0 (no delay, most impact) to 16 (most delay, least impact).

Note:  Prior to Enginuity 5772, the maximum value for priority is 10.

To set the RDF priority value for device group dg_rdfg_140 to 5:

symqos -g dg_rdfg140 set RDF priority 5

 

   2. [   ]    Type the symrdf –g GroupName establish –full command to start the establish operation for the specified device group.

To start the establish operation for group dg_rdfg140:

symrdf –g dg_rdfg140 establish –full –noprompt

 

   3. [   ]    Type the symrdf –g GroupName query command to monitor the progress of the establish operation.

Check the output of the query command to make sure the number of invalid tracks owed from the R1 to the R2 is decreasing. This value is in the R2 Inv Tracks column.

Repeat the query until the devices are Synchronized.

Task 16:  Set the group mode

                       

When all the device tracks have finished copying, the RDF device state is Synchronized.

   1. [   ]    Type the symrdf –g GroupName set mode Mode to set the replication mode for the group.

To set the the replication mode for group dg_rfdg40 to synchronous:

symrdf -g dg_rdfg140 set mode sync -noprompt